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The Big Step Up To 1.5 KW

from Bill Leonard, N0CU on April 8, 2009
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The Big Step Up To 1.5 KW

Although many hams look at upgrading from 150 to 1500 watts as “only 10 dB”, for some the change may seem more like a “giant leap” than a small step. When I decided to purchase a new “legal limit” HF amplifier, I anticipated that I might encounter some of the common problems (RFI, RF in the shack, etc) associated with high power, but I didn’t anticipate needing several months to resolve problems with low output power and persistent arcing. Although problems with arcing and low output power are not uncommon with high power amplifiers, the causes commonly associated with them (parasitic oscillations, “soft” tubes and improper tune up procedure) were not contributors to the problems I was having. My problems resulted from a combination of defective and improperly assembled/aligned parts in the amplifier, and two different antennas that even though were rated for “full legal power”, failed in less than two minutes at 1500 watts. I thought it might be helpful to document my experience to provide additional troubleshooting ideas for anyone encountering similar problems. In an attempt to keep the focus on the types of problems and their solutions, I chose to leave out any references to manufacturers and/or model numbers.

Initial problems and interesting observations:
1) Amplifier inspection:

* Loose hardware and solder flash found inside the new amplifier: Two loose nuts and a screw were found inside the amplifier as it came from the factory. It did not appear that they had fallen off any of the amplifier assemblies during shipment. Also, there were several large pieces of solder flash in the area of the output tank circuit. One unusually large piece fell in such a way that it was actually shorting two turns on the output tank coil.

* Defective Bandswitch:
* A crack was found in one of the ceramic wafers near one of the mounting posts: Although this problem was not considered serious at the time, my decision to go ahead and fix it was quite fortuitous since it led me to discover the other (more serious) defect with the bandswitch.

* Deformed wiper contact (Figure 1): One of the wiper contacts on one of the bandswitch wafers was bent such that it was not making contact for any position of the switch. This defect turned out to be a significant contributor to both the arcing problem and the low output power problem. It was very hard to see this defect, and it was not noticed until after I had started to remove the wires connected to the bandswitch.

* Mis-aligned plate tuning capacitor: The plate tuning capacitor has four adjustment screws that are used to center the fixed plate assembly relative to the moving plates. When properly set, both rotor to stator gaps should have been at least 0.125 inches (which corresponds to a breakdown voltage of about 4.5 KV). These screws had not been adjusted properly and the smallest gap to ground was less than 0.10 inches, while the other gap to ground was over 0.20 inches. In addition to a lower breakdown voltage, mis-aligned variable capacitors will also exhibit a different capacitance range.

* Improperly adjusted arc voltage limiter (Figure 2): There is a voltage limiting gap built into my amplifier. This gap is designed to be the point at which any arcing will occur (harmlessly) if the tank voltage gets too high for any reason. It consists of a metal tab mounted to the hot side of the plate tuning capacitor. This tab is bent to create a specified gap to the grounded side of the tuning capacitor. For my amplifier, this gap should be set at about 0.11 inches, which is slightly less than the specified gap across the plates of the plate tuning capacitor. The 0.11 inch gap should limit the maximum voltage that can be developed across the plate tuning capacitor to about 4 KV. However, in my amplifier the gap was over 0.25 inches. This resulted in arcing always occurring across either the plate tuning capacitor or the output tank bandswitch.

2) Low output power:
* I could not get the output power on some bands to go above 1 KW, even with 105 watts of drive power. The amplifier is specified to deliver 1500 watts out with 100 watts drive.

* On some bands, I could not find a setting for the plate/load capacitors that would result in maximum output power. Arcing would always start before I reached a maximum, even when using a 50 ohm dummy load.

* On some bands, after tuning up to the point just before the on-set of arcing, the final position of the pointer on the plate tuning capacitor knob would be well outside the normal (banded) region marked on the front panel of the amplifier.

* As it came from the factory, the amplifier input SWR was between 1.5 and 2.0:1 on all bands. The minimum SWR was always at one of the band edges (ie, no resonance found on any band), which suggested that none of the bands had been tuned for minimum SWR. The amplifier is specified to have a minimum input SWR for each band of less than 1.2:1 at resonance. Although I initially dismissed this condition as being unimportant, I later determined that it was a contributor to my low output power problem.

3) Power meter accuracy:
* One day I noticed the output power reading on the amplifier power meter went from 1500 watts to over 2200 watts when I simply switched from a 50 ohm dummy load to a dipole (after re-tuning the output tank). Since I held the input power constant at 2400 watts, and the amplifier was not getting anywhere close to 92% efficiency, it was obvious that reading on the amplifier power meter was erroneous. I then switched to my vertical antenna and re-tuned. The power reading on the amplifier meter dropped to only 1000 watts (again, the input power was set at 2400 watts).

4) Arcing:
From day one, I would consistently hear arcing inside the amplifier while tuning up, even when using a 50 ohm dummy load. Sometimes, after tuning up with no arcing, arcing would start for no apparent reason after running maximum power for a short period of time. The symptoms associated with these arcing events were:

* A loud hissing sound from inside the amplifier

* Both plate and grid current meter reading would abruptly drop nearly to zero

* A bright glow from inside the cabinet in the area of the output tank circuit.

* No popping, banging, or shaking of the cabinet, no blown fuses (with one exception, discussed later) or diodes, and the amplifier did not (as one ham said about his arcing problem) “jump one foot off of the table”. Once started, the arcing would continue indefinitely until some action was taken. After an arcing event, normal amplifier performance would resume, with no indication of degraded performance.

* The symptoms didn’t change with load type.
* I never encountered arcing at output power levels below ~700 watts.
* I later noticed that a carbon track had formed on one of the bandswitch wafers (Figure 3). This track, which formed after only about 20 short duration arcing events, was in exactly the same place that other hams have reported arcing problems with this model amplifier.

5) RFI:
As expected, RF interference that did not exist at the 100 watt power level started affecting audio and TV equipment, telephones, and radio equipment when the amplifier output power was increased above the 500 watt level.

Solutions:
1) I addressed all of the workmanship/component problems before starting in on troubleshooting the two primary problems: arcing and low output power.

2) Arcing:
I decided to tackle this problem first. The numerous comments I received from other hams regarding my problems all fell into one of two categories: parasitic oscillations or, I didn’t know how to tune up a linear amplifier. In my experience with high power, tube type HF amplifiers, unstable amplifiers usually exhibit one or more of the following symptoms:

* Plate and/or grid currents peg their respective meters
* Blown fuses
* One or more components (diodes, resistors, tubes, etc) shorted or open
* Erratic plate and grid current fluctuations during tune up

Since my amplifier was not exhibiting any of these symptoms, I started out with the assumption that something other than parasitic oscillations was causing one or more breakdown voltages to be exceeded:

* After reviewing the design and having several discussions with the tech rep at the amplifier factory, I concluded that their design has reasonable margins with respect to breakdown voltages, as long as the load SWR is kept below about 3:1.

* As it turned out, simply fixing the workmanship/component problems noted above resolved my arcing problem. My suspicion is that the defective bandswitch was making it impossible to properly tune the output tank because the wrong inductance value was being selected. This condition could create the same excessively high voltages that would occur if the amplifier was not tuned properly, or was working into a very high SWR. Improper loading on the amplifier tube(s) can easily result in the plate voltage exceeding the ~7 Kv design limit. This theory could also explain both the inability to find a maximum output power setting during the tuning process, and why the position of the plate tuning capacitor ending up outside of the “normal” range indicated on the front panel.

3) Low output power:
* The defective bandswitch was also contributing to the low output power problem. After replacing the bandswitch, I was able to get to 1.5 Kw on all bands except 20M (where 1 Kw was the maximum).

* Although the amplifier input SWR never exceeded 2.0:1, none of the bands met the specified 1.2:1 or less at resonance. Upon closer inspection, I was surprised to see that on several bands my transmitter was partially shutting down due to its output SWR protection circuit activating. On 20M, the transmitter was only putting out 70 watts, instead of the usual 105 watts. This was puzzling since I had previously checked this transmitter with antennas that had SWRs approaching 2.0:1, and had not observed any significant power reduction. Clearly, the reduced drive level was at least part of the reason I was not getting 1500 watts out of the amplifier. It appears that there is some kind of interaction between the transmitter SWR sensing circuit and the amplifier that caused the transmitter to think it was seeing a SWR>2:1. Aligning all of the input circuits for minimum SWR at band center resulted in a minimum input SWR of 1.1:1 or better on all bands, and raised the transmitter output to at least 100 watts on all bands. Now the amplifier put out 1500 watts on all bands into a 50 ohm load. The improvement was especially significant on 20 M where my maximum output went from 1000 to 1500 watts!

4) Power meter accuracy:
* I decided to hook up two additional external true power meters from different manufacturers to compare with the internal power meter in the amplifier. At 1500 watts, all three meters compared closely (within 100 watts) when using a 50 ohm load. However, as the SWR increased, the readings on the internal amplifier meter started to diverge from those of the two external meters. It was then that I recalled a statement in the operation manual for my amplifier: “...Accurate peak envelope power readings are given when the amplifier is connected to a 50 ohm non- reactive load. If the amplifier is used with a mis-matched load, the power meter will read higher or lower than normal by a ratio up to the value of the SWR.” What this is statement is saying is that the amplifier “power” meter is only measuring the voltage at the antenna output, and converting that voltage reading to a power reading on the meter assuming a purely resistive 50 ohm load. Figure 4 shows how a “peak voltage” power measurement can vary with SWR. To keep it simple, I assumed a purely resistive load. I verified this result with the amplifier set at 1000 watts into a 25 ohm load (two 50 ohm loads in parallel). The amplifier power indication was only 440 watts. So, before getting overly concerned about a low output power indication from your amplifier power meter, verify the reading with a second “true” power meter of known accuracy.

5) RFI:
Since there is an abundance of information available on this topic, all I will say is that I found it necessary to incorporate a number of the fixes (filters, significantly improved station RF grounding, RF chokes in some of the commercial electronics and radio equipment signal cables and AC power cords, relocation of some antennas, etc.) that are described in Reference 1. Not only did these problems require several months of troubleshooting and a number of changes/additions to the station, I also encountered a problem that I have not seen referenced anywhere: adding the recommended AC power line common mode choke to my sub-woofer amplifier caused it to immediately, and catastrophically fail. The manufacturer of this amplifier later conceded that the in-line choke I added probably upset the sensitive sequential power-on circuitry in the amplifier’s power supply. With all four power FETs blown and the unit out of warranty, there went an unplanned $150 (to a different sub-woofer manufacturer!). The new sub- woofer amplifier has not had any problem with the in-line chokes.

Success (Almost):
After all of the fixes mentioned above had been incorporated, and a successful trial run into a 50 ohm dummy load at 1.5 Kw with no arcing, I was confident that the arcing problem was solved. I decided to run the amplifier into a commercial multi- band vertical. After about a minute at 1.5 Kw, I heard an unusually loud arc. It turned out that even though antenna manufacturer rates this antenna for “full legal limit” power in their sales literature, they told me on the phone that key down power must be limited to less than 500 watts to prevent damaging the small (500V) mica capacitors they use as a matching element for 80M.

While waiting for the parts to fix my vertical, and still feeling confident about my amplifier, I tried loading up into my trap dipole. Again, after several minutes at 1.5 Kw, I heard another loud arc. A check of the antenna showed that on all bands the SWR had increased to over 10:1. This time, it was a commercial balun that had failed. After replacing the balun with one from a different manufacturer (which is rated for 2 Kw continuous), I loaded up again into the dipole and was starting to feel optimistic after several minutes when I heard the loudest “bang” I had ever heard from any amplifier. The amplifier immediately went dead (no AC power). Both 15 amp fuses in the amplifier had blown. This is the only time that the amplifier did not return to normal operation after an arcing event. It turned out that I had blown a ½ inch diameter hole through one of the 40 M traps (which again, I thought were rated for 1.5Kw). To solve this problem, I decided to build my own traps using “doorknob” high voltage capacitors and wire rated for 600 volts.

Success (Finally!!!):
I can now put 1.5 Kw into my dipole on all bands without arcing. I can easily find the maximum output power point and the plate tuning capacitor ends up in the designated position on all bands. The amplifier is also very tolerant of mis-tuning of the plate and load capacitors. While running 1.5 Kw into the antenna (which has a 1.6:1 SWR), I can de-tune either/both the plate and load capacitors enough to drop the output power by 500 watts with no signs of arcing or other unusual behavior.

Summary:
A problem free transition up to 1.5 KW may occur for some, but for others, troubleshooting and unanticipated modifications/upgrades to the station may be required in order to run this much power. Below is a summary of my suggestions:

1) Inspect the amplifier thoroughly: For newly acquired amplifiers, new or old, an internal inspection should be done before the initial turn-on. Look for loose hardware, bad solder joints, solder flash, defective band switches, improperly aligned tuning capacitors, incorrect arc suppression gaps, any signs of arcing (especially on bandswitches), etc

2) Arcing: Start by verifying that the correct tune-up procedure is being used. Then try to determine the most likely cause (parasitic oscillations, exceeding antenna power handling capability, defective amplifier components, etc). Carefully note all symptoms associated with an arcing event (ie, what happens to the plate current, grid current, output power, positions of the variable components relative to where they should be, etc). Don’t assume that your arcing problems are due to parasitic oscillations or incorrect tune-up procedure. Although parasitic oscillations should be suspected with older amplifiers (especially ones that have not been updated with the recommended modifications to address this problem), this is not likely to be the problem in newer amplifiers currently in production. Finding the real cause of the arcing may be harder than fixing the problem. Also, don’t assume that there is only one cause for the arcing.

In my case, there were several independent contributors to both of my problems. Make sure you know the real power limitations of all the components that will be exposed to the high power levels. Don’t assume that terms like “full legal limit” mean key down indefinitely at 1.5 Kw. There are two different ratings that need to be understood: peak voltage and average power. Ratings like “1500 watts PEP” usually address only the voltage limitations. In addition, it is also important to know the average power handling capability, which is usually driven by thermal limitations. Thermal limitations result not only from much heat a component generates, but also how well the design removes that heat. In the case of my 40 M trap, it had plenty of voltage (ie, PEP) margin, but eventually failed under key down conditions because the heat generated by the I2R losses in the coil could not be dissipated before the part got too hot and melted the plastic form, causing a short. Over half of my arcing problems occurred after the key down time exceeded 60 seconds. Many component and equipment manufactures don’t address their continuous duty cycle (ie, key down indefinitely) specifications because they are frequently one half, or less, of their “PEP” or “full legal limit” performance claims.

On the other hand, some manufacturers actually highlight their continuous duty cycle performance to emphasize the robustness of their design. However, there is almost always a much higher price associated with this higher level of performance. Do Not; continue operating an amplifier that has a persistent arcing problem until the cause, and the potential effects, are understood. Random, infrequently occurring arcs across a voltage limiting gap (or even the plates of a tuning capacitor) may be of minimal concern if the cause is known (ie, connected to the wrong antenna). The small, 1/8 inch deep carbon channel that was burned into my bandswitch resulted after less than 20 very short duration arcing events. A graphic example of the catastrophic result which would have resulted if I had continued operating with this problem can be seen in Figure 5. This photo, along with others’, can be seen on the Measures’ website (www.sophis.org/). It is also important to realize that once carbon tracks form, the breakdown voltage required to initiate future arcing events across them drops significantly (by 2-3 times or more) from the original breakdown voltage. So the problem, if not resolved, is will only get worse with time.

3) RFI: Plan on having to buy, borrow, or steal a copy of Reference 1

4) Low output power: Don’t just assume that problems with low output power are a result of weak tubes or improper tuned-up procedure. Confirm the power readings with an accurate true power meter, then verify that the transmitter is driving the amplifier with the expected power, and check that the plate and load capacitors are positioned appropriately after tuning up.

5) Reliability: Sending a new item back to the factory for warranty work is always frustrating and time consuming. Additionally, in the case of high power HF amplifiers, it can also require a significant effort (my amplifier must be partially disassembled and packed into three separate boxes) and can be quite expensive (total weight over 75 pounds). Anyone who is not willing, or able to do their own troubleshooting on a high power amplifier might want to spend a little extra time reading the reviews on comparable models by different manufacturers before making a decision.

Bill Leonard
N0CU

Figure 1: Defective Bandswitch (Bent tab)

Figure 2: Arc Voltage Limiter

Figure 3: Arced Bandswitch in My Amplifier

Figure 4: “Peak Voltage” Power Meter Measurement Uncertainty vs. SWR (Actual power equals 1000 watts)

Figure 5: The Final Result (Output Tank Bandswitch on the Measure’s Website)

Member Comments:
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The Big Step Up To 1.5 KW  
by W2BLC on April 8, 2009 Mail this to a friend!
Perhaps I missed it, but what make/model amplifier are you talking about? Some manufacturers suffer from low quality control - but, not all.
 
The Big Step Up To 1.5 KW  
by AB3EN on April 8, 2009 Mail this to a friend!
WOW what a horror story. I have had very good luck with two amps, not 1500W's but the SB200 and TenTec Centaur both have been problem free. I suspect it is the make of amp not the output level that is at issue. I would have mailed the "amp" back to the mfg with a letter from my attorney asking for my money and all my expenses.
AB3EN
 
The Big Step Up To 1.5 KW  
by K3TN on April 8, 2009 Mail this to a friend!
There are several references to reference 1, but no "Reference 1"!

To what does "Reference 1" refer to?

Referentially, John K3TN
 
The Big Step Up To 1.5 KW  
by K9RJ on April 8, 2009 Mail this to a friend!
The lesson learned is you get what you pay for. I have an ACOM 2000A, Drake L-7, Henry 2K-4 and HB 3-1000Z and have never had the amp problems. A new amp that has all these issues should be sent back - it is a piece of junk! I can guess where it was made ... No one should have to put up with something like this.

It is true you have more RFI issues with 1500W that can take some detective work to sort out.
 
RE: The Big Step Up To 1.5 KW  
by W8JI on April 8, 2009 Mail this to a friend!
It sounds like a couple of amplifier problems, some shipping problems, and some antenna issues combined to make a long mess.

If you had a greatly misaligned tuning cap and cracked band switch that amp might have taken a pretty big hit on the front knobs during shipping. That can bend parts up front.

I would have sent the amp back for that.

I watched Fed Ex ground hold a 50 pound amp above my four foot tall fence and drop it. It hit the driveway after a four or five foot fall flat with a thud, and the box looked fine. Then they were getting ready to drop the tube over the fence the same way but I yelled in time to stop them. Inside was much like you describe with misaligned and broken parts.

They tried to deny the damage because the box wasn't all beat up.

Antenna failures, like a trap blowing out or a balun, can trigger problems all through the system because all that RF has no where to go during the fault.

Anyway hopefully that is it for you.

73 Tom



 
RE: The Big Step Up To 1.5 KW  
by G3LBS on April 8, 2009 Mail this to a friend!
Get rid of all traps and baluns. With ladder line to dipoles and quads you can really pump the power.
 
RE: The Big Step Up To 1.5 KW  
by KB9CRY on April 8, 2009 Mail this to a friend!
I've never had those problems with my amps.
 
The Big Step Up To 1.5 KW  
by NN4E on April 8, 2009 Mail this to a friend!
No need to mention the make :-) One can tell right away that it looks like it is an Ameritron!
 
RE: The Big Step Up To 1.5 KW  
by N6NKN on April 8, 2009 Mail this to a friend!
Why not just send the POS back??

Rick N6NKN
 
RE: The Big Step Up To 1.5 KW  
by N0CU on April 8, 2009 Mail this to a friend!
I intentiionally left out references to mfgs because I wanted readers to focus on symptoms and fixes, not possible design/quality controls problems with specific brands/models. With that said, the amp was an Ameritron AL-82 and the vertical was a GAP Challenger.
 
RE: The Big Step Up To 1.5 KW  
by N0CU on April 8, 2009 Mail this to a friend!
Sorry about the Reference mistake. I ended up with only the ARRL RFI Handbook as a reference.
 
RE: The Big Step Up To 1.5 KW  
by K0BG on April 8, 2009 Mail this to a friend!
In the last 12 months or so, I have worked on an ALS-572, and an ALS-80B. Both had solder problems with the tank circuit.

In the case of the 572, neither the 40 or 20 meter taps were soldered. It was more than obvious that neither one passed final inspection (if there was one).

The 80B had a broken band switch. It appeared that the screw holding it was tightened to much, but it could have been damaged in shipping to the dealer (it was purchased across the counter at AES). MFJ did repair the amp (nearly 4 week turnaround), and it was returned with a notation on the repair slip as "fully tested". It didn't work when it arrived for two reasons. One, the HV wire to the choke wasn't soldered, and had dropped close enough to the chassis to arc. A line side fuse was missing as well.

These problems are not design problems, they're quality control problems. The unfortunate part is, quality control has always been the Achilles heel of MFJ. Let's hope they read this, and act accordingly.

Alan, KØBG
www.k0bg.com
 
RE: The Big Step Up To 1.5 KW  
by N0YXB on April 8, 2009 Mail this to a friend!
Nice article Bill. Thanks for sharing your experiences so others can learn.

Vince
N0YXB
 
RE: The Big Step Up To 1.5 KW  
by N0CU on April 8, 2009 Mail this to a friend!
Shipping damage is certainly a reasonable possibility, however, since:
-the box showed no signs of damage from shipment
-the amplifier showed no signs of damage from shipment
-only one contact on the switch was deformed
I dismissed this possibility early on. I should mention in Ameritron's defense, they do ship the amp in three separate boxes (amp, tubes, and transformer). However, that does raise the question about whether these amps ever get tested before shippment? I could be wrong, but the switch contacts are quite malliable and I don't see how only one contact could be bent to a 90 degree angle by a blow to the shaft. Given the difficulty I had removing/re-installing the large tank coil assembly, I am quite confident that the technician assemblying the tank assembly simply bumped it with a soldering iron or some other tool.
Also, I wouldn't describe the capacitor as being "greatly" misaligned. In fact, if it hadn't been for the arcs occurring there when they shouldn't have, I would not have even suspected the problem. Similar to the arc suppressor gap being incorrect, I think these are just quality control issues.
 
RE: The Big Step Up To 1.5 KW  
by AB0Z on April 8, 2009 Mail this to a friend!
Really nice article, Bill! I personally would have given up immediately at the very first inspection. But, it is really good to know how to put things right if they do go wrong.

I worked barefoot for over a decade until buying an ACOM amp. You know what you have just bought when you open it up for the first time. My unit inside looked like it came from a Swiss watchmaker, so it is not necessarily true that all amps are badly made at the factory.
 
RE: The Big Step Up To 1.5 KW  
by N0CU on April 8, 2009 Mail this to a friend!
"Why not just send the POS back??"
Once I fixed the problems, it has been a great amp. It has only arced once in the past 6 months, and that was my fault (I tried to load into the wrong antenna). I do like the design of the AL-82, I think Ameritron uses good parts, and as a company they are very committed to helping their customers resolve any/all problems. An ALPHA it is not-but it wasn't designed to compete with that part of the market. Would I buy another AL-82: without hesitation. Would I recommend them to others: not necessarily. Anyone who is not willing/able to troubleshoot and resolve problems with a high power amp, or not willing to deal with the hassle and expense of boxing the amp up and sending it back to the factory, probably should spend some time researching other options and then decide how much more they are willing to paying for better quality control.
 
RE: The Big Step Up To 1.5 KW  
by KB6QXM on April 8, 2009 Mail this to a friend!
OUTSTANDING! Now these are the type the articles that I would like to see on eham. Technical, useful and real world.

This is the way that all hams used to be before the watering down of the licensing system.

Bravo!!!

I will say that lately there have been some outstanding collection of technical articles, such as the loop antenna article. Is there anyone on here that is saving the articles and putting these on their websites for people to access at anytime?

This motivates me to build a site specifically for this purpose, but I do not want to reinvent the wheel. I have seen some nice ham radio websites that are dedicated to technical articles, but the sites need a bit more "technical engineering" behind the sites themselves. One site that I will not mention has a lot of technical articles, but the UI (user interface) is terrible. The site can not be easy searched or indexed. Terrible.

There are a lot of hams that are great engineers, but cannot design a good website. Maybe with these new hams that are less technical in analog design or CW proficancy, maybe they can bring web development to the table. Not just WYSIWYG developers, but people that write scripts, integrate server-based flash into the site. Good bottom-up design. Any takers?

These articles need to be saved as they are technical and practical to the more technically savvy hams.

73



Any takers?
 
RE: The Big Step Up To 1.5 KW  
by AI8P on April 8, 2009 Mail this to a friend!
My experience is a QRO Technologies amp into a Gap Titan and there were no issues with either. I also run full legal into a DX Engineering 80M dipole, also without incident. I did need to add a Low Pass filter in the amp output to keep RFI out of my TV and stereo - the Bencher one worked fine for me.

Your mileage may vary!

de Dennis AI8P
 
RE: The Big Step Up To 1.5 KW  
by W7ETA on April 8, 2009 Mail this to a friend!
Outstanding prose.

Great article.

Almost as enjoyable to read as a Sherlock Holmes short story.

73
Bob
 
RE: The Big Step Up To 1.5 KW  
by K5UJ on April 8, 2009 Mail this to a friend!
<<<I watched Fed Ex ground hold a 50 pound amp above my four foot tall fence and drop it. It hit the driveway after a four or five foot fall flat with a thud, and the box looked fine. Then they were getting ready to drop the tube over the fence the same way but I yelled in time to stop them. Inside was much like you describe with misaligned and broken parts.>>>

Too bad you didn't have a chance to grab a video camera--that would have made a great video for YouTube.

When I was planning my station one of the first things I decided was to try to make every element legal limit rated whether I ever ran 1.5 kw or not because if I did, I didn't want to have to redo things. I wanted to be able to simply install the amp and run it. Well, about a year later I bought a new Ten Tec Centurion. I had trouble with RF in the exciter's audio but in my case that was fixed with some ferrite chokes, and a shorter run to the ground rods and a shack star ground using a single point.

I want to use this opportunity to make a point about feedline, tuners and so on being rated for legal limit: These measures (especially with feedline) while important for power handlng, are also good for low power operating. The reason is that often, a high power feed is also a _low loss_ feed. Some hams who operate QRP make the mistake of thinking they can get by with RG58U because it can handle 5 watts. But a 100 or 150 foot run of such a coax, even at 1:1 vswr will deliver a lot of loss. Actually, they need a much higher power rated feed, but for a different reason, that such a feedline will deliver a greater percentage of their output to the feedpoint. Save the 58U for jumpers to the oscillosope and amp (if you get one) and speaking of amps, for heaven's sake if you go QRO, invest in some kind of 1.5 kw dummy load and tune up into it before tuning on your antenna, and then only if you have to!
 
RE: The Big Step Up To 1.5 KW  
by K6AER on April 8, 2009 Mail this to a friend!
Very nice article. I must add a watt meter is only accurate when it is used into the designed load impedance.

On another note:

I go to Dayton every year. Working for several vendors I get their early on Thursday so to aid in set up. As a result I see many for the vendors setting up as well.

In the hockey arena, Ameritron is setting up all their amplifiers with the tops off. About three years ago I stopped and starting poking around the inside of the amplifier on display and found a lot of loose hardware including several critical areas in the tank circuit section. I pointed this out to the young man setting up the display that this does not bode well for quality control. I noticed in many cases there was no lock nuts between the metal work where a screw and nut was involved in the assembly.

Two years ago when I went by the Ameritron display I found the same bunch of amplifiers again with very loose hardware. Again I noticed no lock nuts on much of the hardware.

Last year I went by the Ameritron display and saw that the amplifiers all had lock nuts on the screw mechanicals and much to Ameritron’s credit the same young man was making sure all the hardware was tight. He looked up and smiled.

Despite the poor quality control issues often discussed with Ameritron they do fill a marketing nitch and produce a good product for the amount of money spent on their products. Shipping vibration is always a problem. With any piece of electronic gear you should inspect that nothing has come loose.

Last month I shipped an Alpha 86 to Texas and had Alpha in Bolder, CO do the shipping. They placed the amplifier into a hard foam custom box. The transformer was separated and placed into another special foam box. Both boxes were strapped to a shipping pallet and shipped Fed-X surface fright. The amplifier arrived in good shape but the new owner told me the front feet had vibrated loose. These feet were all tight with proper hardware.

Bottom line is always inspect the product you receive.
 
RE: The Big Step Up To 1.5 KW  
by N0CU on April 8, 2009 Mail this to a friend!
Mike,
I have always read that "true power" can be obtained from a true power meter by subtracting the reflected power from the forward power. Is that not correct?
Bill N0CU
 
RE: The Big Step Up To 1.5 KW  
by G3LBS on April 8, 2009 Mail this to a friend!
In addition to advising ladder line to a differential link tuner, no baluns, no traps, I advise only one tube in the amp, something like an 8877. Otherwise monitor each tube current.
W2/G3LBS.
 
RE: The Big Step Up To 1.5 KW  
by K0BG on April 8, 2009 Mail this to a friend!
Bill, every time I have broached the wattmeter scenario you and Mike have, I get burned by someone. However, I have to side with Mike.

How much they are off when the impedance gets reactive depends on design, the phase angle involved, and probably a few things I've missed.

The interesting part is, I can't remember the last time I saw an ad for a wattmeter which actually stated what impedance it was designed for, nor have I seen any mention of accuracy outside the nominal impedance, whatever that may be (I'm assuming 50 ohms, but who knows?).

I think we're all in agreement that internal ones seemingly are lousy, but heck, some external ones are too! What's more, it doesn't make too much difference what you pay for them, if you believe the recent ARRL tests of a few popular ones.

You'd think that if you'd paid the kind of money you pay Alpha for their unit, it would be somewhat better measuring through a wider range of impedance, but that doesn't appear to be the case either.

Over the years, I've come to the conclusion, that close enough is good enough, but you wouldn't think so from reading these pages.

Alan, KØBG
www.k0bg.com
 
The Big Step Up To 1.5 KW  
by AI2IA on April 8, 2009 Mail this to a friend!
It is a very good idea for all hams to read up on and get familiar with RF linear amplifiers. Some hands on experience with a buddy's amp can teach you a lot. After you do that, you might want to ask yourself some questions:

How much of my signal do I lose in my transmission line before it ever gets to my antenna? If you lost 3dB in your line maybe you would greatly reduce that loss with RG-213/U or open wire line.

Is my antenna efficient? It is cheaper and very effective to improve the antenna, transmission, and matching than to add a linear amplifier without first making your antenna and transmission line the best they can be.

How about my connectors? N type connectors can work efficiently right on through the 33 cm band. When properly installed, most are waterproof and will have no problem with full legal power.

Do I understand the meaning behind the increases and decreases in S-units and in decibels? Do I know what it means when I see a change in received signal of one
S-unit? If I quadruple my power output, how much will the other ham probably see as an increase on his S-unit meter, all other conditions being the same?

Have I considered the cost versus the alternatives, and do I know the pros and cons of solid state versus tube amplifiers?

Will I get that much use out of an amplifier to justify the cost, the bulk and wiring, and the complexity and maintenance?
 
RE: The Big Step Up To 1.5 KW  
by W4VR on April 8, 2009 Mail this to a friend!
It's like the old saying goes, "you get your money's worth." However, there is no excuse for loose nuts, components with only one end soldered to a terminal and the other end hanging, etc. When you order one of these amps, it's important to take the case off and check everything out, including missed solder connections. The only hi-power amplifiers I ever owned were ETO/Alpha, and I used them for years with no problems, even without ever taking the case off except to plug in the tubes and transformer. I now use very expensive solid state amplfiers...and I hate to think of the consequences if one ever failed!
 
RE: The Big Step Up To 1.5 KW  
by NO9E on April 8, 2009 Mail this to a friend!
Great attitude from N0CU to fix it rather than only complain. One loses the same amount of time but when fixing one learns something. And there is a nice story to tell later....
 
The Big Step Up To 1.5 KW  
by K4CC on April 8, 2009 Mail this to a friend!
Traps can be a problem for sure. When I first put my Alpha 87 on line, After 20-30 seconds, the SWR went sky high. I researched and found Cushcraft considers legal limit to be 1000 watts ICS not 1500 key down. I changed antennas to a trapless and had no more problems. My Alpha Delta dipole traps never failed however.

Great article!

Cary
K4CC
 
RE: The Big Step Up To 1.5 KW  
by N6AJR on April 8, 2009 Mail this to a friend!
well mostly I run the orion into an Alpha 87a and that into either a gap voyager or a 3 ele steppir. so far no problems but then again I only run power on the gap in its "happy" range and only 100 watts when the swr is higher. gap will tell you that if you run power when antenna is out of resonance you will either blow the capacitor or melt the internal wires.

I also use a tl 922 on the TS 2000, and an ALS 600 on the pegasus, and an IC2-KL on the 746 pro and an AL 1200 on the ft990.. II have had little to no problems on any of these amps.

I also have up a hustler 5btv and a Alpha delta sloper, but once againg these are only run in to their " happy" areas and not where the swr is high. they will smoke badly when operated out of resonance. so the AD wire is set at the cw end of the bands and thye voyyager is set in the phone portion of the bands and of course the steppir goes any where, but I do not transmit while it is in the process of tuning.

I have also had many other amps, like 3 ameritron 811's and a couple of 811 H's, several clipperton L's and a bunch of sweep tube amps over the years, but I like the autotune features the best so mostly I use the Orion / Alpha combo.

I too have had shipping disasters with all 3, the post office, UPS, and fed ex. so far I have not seen DHL break anything (yet) but pick up the expensive stuff yourself.
 
RE: The Big Step Up To 1.5 KW  
by K9FON on April 8, 2009 Mail this to a friend!
I dont have the $$ to buy a new amp so i stick with the tried and true. Im using a 40 year old Swan MK II, and so far no pops or arching. But my tuner doesnt like the higher power that the amp puts out so i have to be careful.
 
The Big Step Up To 1.5 KW  
by N0AH on April 8, 2009 Mail this to a friend!
This amp screams "I'm Ameritron and I suck"

Amps are good but a great antenna is better regarding production in a contest or DX pile up- A loaded amp will never be a substitute for good operating skill. Just listen to all the lids on 40M phone now who lay waste to this new opportunity called operating simplex into EU.

I do just love the good DX operator ignoring the east coast while west coast is rarely hearing them on the gray line. Even when they call W6/W7, some guy in Florida yells and brags about his amp- After operating a number of DX'peditions, I find myself ignoring the obvious amplifiers and to listen for the areas of most need and/or interest. Loud just doesn't always get it for me- And yes, amps screw up everything in the shack- admit it or not-

Once again, my money is that this amp is AmErItRoN......MFJ, same poo poo
 
The Big Step Up To 1.5 KW  
by N0AH on April 8, 2009 Mail this to a friend!
Does anyone really have any idea how much it cost to ship in an amp for repairs? Hint.....most weigh more than you- and just removing the tubes for safe shipping/packing can damage sockets etc.....I've owned an Ameritron 811, 800H, and Alpha 99. The 811 lasted about 4 months then I sold for parts. The 800H was rebuilt by a good friend of mine but had to be gutted and went to Mississippi at least once in 2 years. The Ameritron was fb- If you really want an amp, shop the used market and save hundreds of dollars that you can use to send it in to the factory and have it rebuilt for safe use.
 
The Big Step Up To 1.5 KW  
by N9AOP on April 8, 2009 Mail this to a friend!
I have a centurion from TenTec and it came well packaged and was put together properly. That outfit takes pride in how they put things together.

I also have an 811H and it was not so well packaged. But the amp was put together well and I have not had any issues with it. From what you hear about MFJ, I guess it depends on what particular student put the product together on a given day after school. You would really think that they would have a knowledgable person qc the product before it goes out the door because the returns under warrenty for them to correct must not help the bottom line.
 
RE: The Big Step Up To 1.5 KW  
by K9FON on April 8, 2009 Mail this to a friend!
The 811H i had worked pretty well. I did have a tube short but that was not the fault of the amp just junk tubes used in the amp. I traded my 811H for my Swan MK II. I lost 160 meters, but oh well.
 
The Big Step Up To 1.5 KW  
by AD7WN on April 8, 2009 Mail this to a friend!
Bill, what a horror story! You didn't have to mention that it was Ameritron for all of us to know that was the case.

This is strictly a case of lousy quality control at Ameritron. Obviously they didn't bother even firing it up to see if it would work. They just shipped the darned thing.

Ameritron does turn out good quality amplifiers. They just don't do it consistently. It must all depend on which of their junior high dropouts puts it together.

Your article should go down as an eHam Classic. Very well done.

73 de John/AD7WN
 
The Big Step Up To 1.5 KW  
by KD5SFK on April 8, 2009 Mail this to a friend!
Bill,

Well written and thorough article, with pictures! But, I'm afraid you said it best in your first sentence....Seems like an awful lot of trouble for "10 dB"!
 
RE: The Big Step Up To 1.5 KW  
by NB3O on April 8, 2009 Mail this to a friend!
"then decide how much more they are willing to paying for better quality control. "

For some of us, it was worth rolling our own...

Over two decades ago, I copied the design of the Harris RF-110A final section after searching out parts for a couple years. The parts cost about half of an Alpha and I learned a lot about controlling my own quality.
73
 
RE: The Big Step Up To 1.5 KW  
by AB7E on April 8, 2009 Mail this to a friend!
N0CU: "Anyone who is not willing/able to troubleshoot and resolve problems with a high power amp, or not willing to deal with the hassle and expense of boxing the amp up and sending it back to the factory, probably should spend some time researching other options and then decide how much more they are willing to pay for better quality control."

NO9E: "Great attitude from N0CU to fix it rather than only complain."


Those are precisely the kinds of customer attitudes that perpetuate bad quality from manufacturers. If people refused to accept bad quality, companies would soon be forced to learn how to do good manufacturing. And as any manufacturing guy with more than a few dozen brain cells will tell you, good quality control SAVES money, it doesn't cost extra when it is done right. It only costs money when it is attempted after the fact (inspections, rework, etc), and then it's a lost cause anyway. Proper process control is a function of knowledge and commitment, not dollars.

The people who keep buying from MFJ/Ameritron and make excuses for what they got ... deserve exactly what they got.

Dave AB7E

p.s. I wonder how accepting U.S. hams would be of MFJ/Ameritron quality performance if their products were built in China. I bet we'd be hearing different descriptors.

 
Might as well get a HEATHKIT  
by QRZDXR2 on April 9, 2009 Mail this to a friend!
Good article.. wow lots of work and problems. With all that you could have put togeather a heathkit SB 220 and moved on down the road.

One good thing to be said about the old Henry, Collins and other tube amps. They take a licking and keep on ticking. Cheap too used. A watt is a watt.

With todays cost being a factor.. go figure the quality.

Me thinks the gent has some SWR issues also with his amps as he goes up in power. Arc'n is not something the amps normally do unless something is reacting with it.

I know one guy who tried to use RG-58/8X for his amp. Nothing but problems. (special at radio shack) How are they supposed to know.

I know another one that uses his amp and vertical to drive worms out of the ground to go fishing. Added bonus no doubt while ham'n around.

Strange things happen when your dealing with high power.
 
RE: Might as well get a HEATHKIT  
by KF4HR on April 9, 2009 Mail this to a friend!
While I applaud N0CU's efforts to troubleshoot and correct the amp's problems, I think it's a damn shame to have to pay good money for an amp, then have to turn around and troubleshoot it. Obviously the manufacturer used the bare minimum quality components to minimize manufacturing costs - along with possible poor design.

This article drives home the reason why some people opt pay more (sometimes much more) for an Alpha, ACOM, or other higher end amps.

We need more articles like this; if for no other reason, to make hams think twice before they spending their hard earned money on lesser quality products.

Who knows, if hams stopped buying poorly designed products, manufacturers just might turn around and improve their quality.

KF4HR
 
The Big Step Up To 1.5 KW  
by K3PRN on April 9, 2009 Mail this to a friend!
Please give manufacturer and model?
 
RE: The Big Step Up To 1.5 KW  
by KW4N on April 9, 2009 Mail this to a friend!
"You get what you pay for" has little to do with quality. So poor performers should just raise their price???
Quality issues are a management problem. If they choose to put in more inspectors to solve the problem, it won't work but only drive the cost and our price up. The operator on the line should be doing self-inspection. Operator's need to be adequately trained and held accountable. Some operators are just not trainable. eg. Toyota wouldn't move their plant to Mississippi in spite of tremendous financial incentives because they determined the operators were untrainable. They moved it to Canada. Shame on us!

There is no excuse for lousy packing and shipping. The manufacturer's management is responsible for this too. Their responsibility extends right up until the buyer plugs the unit into the wall. If not, they are succumbing to the notion of "never enough time to do it right the first time but lots of time and cost to fix it."
As long as we buyers shamelessly continue to enable and tolerate lousy products by 'hoping for a good one' then we continue to be part of the problem, not the solution.
Dave, KW4N
 
RE: Might as well get a HEATHKIT  
by K5END on April 9, 2009 Mail this to a friend!

"I know another one that uses his amp and vertical to drive worms out of the ground to go fishing"

Those are bio-degradable, organic ground radials.
 
The Big Step Up To 1.5 KW  
by N0CU on April 9, 2009 Mail this to a friend!
“…management decision…” Has anyone ever seen numbers that show how well MFJ is doing as a company? The only metric I have is that they have grown to the point where their ads fill up half the space in every QST, and they continue to do it as other companies cut back to try and survive. Does it seem like there are ten times as many complaints about MFJ products compared to other brands? If so, is this because their products are ten poorer in design/quality or is it because they are the same as their competitors except they sell ten times more product? My point here is: maybe they have some very good management that knows just where to draw the line on spending for better quality so as to make the maximum profit. In my case regarding the AL-82, I did enough research to decide that the $2-8K savings compared to similar amps was well worth my time to fix any problems due to their quality control problems. This decision was based also on the assumption that they had a good design that could eventually be made to work as well as the higher priced units. As I said in my article, my choice may not be the best decision for someone who wants a trouble-free unit and is willing to pay whatever it costs to get one that they won’t have to troubleshoot or pack up and send back to the factory. I have no regrets for my choice, and would do it the same way if I had to do it over.
Bill N0CU
 
RE: The Big Step Up To 1.5 KW  
by AC7CW on April 9, 2009 Mail this to a friend!
I hope the author hotfoots it over to the reviews section and posts a review. People need to be informed regarding what they are getting for their money.
 
The Big Step Up To 1.5 KW  
by WW5AA on April 9, 2009 Mail this to a friend!
Percentage wise, I fix as many Alfa's and Commander's as MFJ amps. I never worry about antenna's since I make my own and rate them at 5K. Folks that buy antenna's and don't look inside of the BOX, are bound to have problems...

73 de Lindy
 
RE: The Big Step Up To 1.5 KW  
by K5UJ on April 9, 2009 Mail this to a friend!
<<<Percentage wise, I fix as many Alfa's and Commander's as MFJ amps.>>>

An owner who doesn't know how to operate an amp can break or damage a high priced amp just as well as a cheap flea market one.
 
RE: The Big Step Up To 1.5 KW  
by WW5AA on April 9, 2009 Mail this to a friend!
....and for the MFJ haters, no one is forcing you to buy from them so quit complaining.

73 de Lindy
 
RE: The Big Step Up To 1.5 KW  
by N0CU on April 9, 2009 Mail this to a friend!
AC7CW: As you requested:

ALPHA__87A________$6500___Rating = 4.7
ALPHA___89________$4000___Rating = 4.7
ALPHA_9500________$9000___Rating = 4.4

AMERITRON_AL-82___$2100___Rating = 4.8
AMERITRON_AL-1200_$2300___Rating = 4.8
AMERITRON_AL-1500_$2900___Rating = 4.8

Any more questions?

Bill N0CU
 
RE: The Big Step Up To 1.5 KW  
by K0IZ on April 9, 2009 Mail this to a friend!
Good article, Bill.

To make it easier on amps and antennas, I recommend tuning up with a "pecker" unit. This has been around for maybe 30 yrs, and is a pulsed audio oscillator that plugs into mike jack. Duty cycle might be 30% or so, depending upon circuit values. Makes for very safe tune ups, easy on tubes, etc.

Circuit is easy to build from scratch, or a small circuit board and parts can be purchased from www.3898pecker.com

This audio pulser is better than using a CW keyer sending dits. Many radios have somewhat different outputs for SSB and CW modes. Using the pecker allows use of the SSB mode.
 
RE: The Big Step Up To 1.5 KW  
by N4KC on April 9, 2009 Mail this to a friend!
I agree that this is a very good article...not because it might keep somebody from buying a particular brand product but because it might encourage someone to inspect, troubleshoot, and repair...regardless of who soldered the thing together.

When I saw the first paragraph, I thought, "Uh oh! Let the MFJ flames begin!" Yes, the guys from Starkville could probably improve QC a bit, but so could most every other manufacturer of anything. MFJ does offer a stunningly high number of practical products for amateurs at truly reasonable prices. They also support all the amateur publications when others are cutting back. And they also attend more hamfests than any other manufacturer I know, maybe keeping some of them in business. The owner himself attends many of them.

I'm no apologist for Mr. Jue, but I'm thankful he's there and does what he and his folks do. I wonder what percentage of ham shacks not only have at least one item from MFJ, Ameritron, HyGain or other affiliated companies, but they actually use one every day. I just did a count. Fifteen! From rotor to antenna switch to keyer to 811 amp to wattmeter to antenna analyzer...and they all worked first time and every time.

Hey, if I buy an ACOM or an Alpha or a TenTec, I'm still going to yank the top off and take a look before I energize the thing. I'll also take trap or balun manufacturer power-handling claims with a grain of salt and error on the side of caution.

(NOTE: surely you've noticed that DX Engineering, one of the finest customer-oriented companies in this space, is now proudly offering the MFJ line to their customers.)

Don N4KC
www.n4kc.com
www.donkeith.com
www.n4kc.blogspot.com
(An open blog dedicated to rapid technological change and
its effect on society, media and amateur radio)


 
The Big Step Up To 1.5 KW  
by WA1RNE on April 9, 2009 Mail this to a friend!

"When I decided to purchase a new “legal limit” HF amplifier, I anticipated that I might encounter some of the common problems (RFI, RF in the shack, etc) associated with high power, but I didn’t anticipate needing several months to resolve problems with low output power and persistent arcing."


>>> Although I applaud your tenacity to get the amplifier running properly, the type and amount of problems you experienced should have resulted in a decision to provide you with a new replacement - along with reimbursement of the return shipping cost.

Not having purchased anything from Ameritron myself, I have no idea what their warranty policies are with regard to defects and workmanship for new products, so maybe they would have provided this level of support had you asked.


Just curious, did you ask for a replacement or did they offer to do so? Given the quality concerns you have documented, your answer may be a key consideration for anyone considering a future amplifier purchase.


...WA1RNE
 
RE: The Big Step Up To 1.5 KW  
by AB7E on April 9, 2009 Mail this to a friend!

You guys who keep defending MFJ are missing the point. Most of the criticism against MFJ isn't about their designs and it usually isn't even about their choice of parts. It's about manufacturing quality. It doesn't cost any more to make a good solder joint than a bad one. It doesn't cost any more to install a part rather than leave it out, at least not when you consider inspection and customer return issues. It doesn't cost any more to tighten a nut versus leaving it loose.

Good manufacturing is fundamentally a function of process control, and in most cases that means simpler flows through the production area, better inventory control, better training of operators, consciously reducing variables to minimize opportunities for error, and an attitude of pride in quality. NONE of those cost extra, and ALL of them SAVE money.

Making excuses for bad behavior merely reinforces bad behavior.

Dave AB7E

 
RE: The Big Step Up To 1.5 KW  
by NO6L on April 9, 2009 Mail this to a friend!
So, let's see, you spent about $3000 for a legal limit amp. It then needs, what, in my shop would cost $500 in labor alone and probably another couple of hundred in parts?

And you came out ahead where.

On top of that, you're somehow concluding that parasitic oscillations cause arcing, they don't. They can't. Read and learn:

http://www.w8ji.com/SB221/sb-221.htm

Now, as a qualifier for me, I like building things, with and without tubes. I'll tackle a legal limit vacuum tube amp or even a vacuum tube mic amp stage. I even use a Viking II on AM. And yes, I prefer to build my amps, after all, what's basically in the vacuum tube HF amp? A tube, two tuning caps, a tank coil, power supply and input circuit. Why even buy one? They're WAY over priced for what you get.

But, I also know when you're wasting time and money. For example, the above $3000 dollars would have gotten you a Tokyo High Power HL-1.5KFX for the same price, or less, and it would just work. No tuning, no concern about arcing, protects itself, and on and on. And in the end you'd be what, 3Db down from legal limit? You can get that back by improving the rest of your station for little to no money. Save the tubes for a home brew project as far as RF amps go. MOSFET amps are now cheaper, after maintenance is considered, than vacuum tube based ones, because there isn't any.

I just don't see the logic, why did you even consider buying this pig? Why didn't you lift the covers to inspect it? I wouldn't even let a Tokyo slip through on this. And then, not send it back when all the defects were found.

The last thing I'd do is write an article about this, I'd be too embarrassed. I'm sorry, but there it is, people avoided it, but it had to be said.

Live and learn, I guess.

73 NO6L
/end of line
 
RE: The Big Step Up To 1.5 KW  
by N0CU on April 9, 2009 Mail this to a friend!
WA1RNE: I didn't need to ask for an ok to return the amp to the factory because Ameritron offered that option to me as soon as I described the problem to them. My choice to troubleshoot vs return was based upon:
-I enjoy working on RF hardware, especially when there is a non-trivial challenge involved
-I felt I had the time, experience, and test equipment needed to solve all of the problems
-I don't enjoy disassembling hardware, packing it into three separate boxes, and then paying somewhere around $80-100 to ship it
-Ameritron willing provided all of the consulting and replacement parts I needed when I needed it
I have no complaints about Ameritron's commitment to make things right.
Bill N0CU
 
RE: The Big Step Up To 1.5 KW  
by N0CU on April 9, 2009 Mail this to a friend!
NO6L: Since you obviously didn't even read my article, I stopped reading your post after the first inaccurate criticism (regarding parasitic oscillations)!
N0CU
 
RE: The Big Step Up To 1.5 KW  
by AK2B on April 9, 2009 Mail this to a friend!
Bill, this article is gives testimony to both your technical skills and you patience. Personally I would have rather dealt with these types of problems somewhere down the road a few years instead of with a brand new shiny amplifier. On the other hand, I do know people that would have done exactly what you did and taken matters into their own hands, if only to make sure the job gets done right.

 
RE: The Big Step Up To 1.5 KW  
by K1BXI on April 9, 2009 Mail this to a friend!
Bill, I won't dispute your comments about QC and loose hardware but the rest of your article reads like someone that was trying to load that amp into something much less than an ideal load, which in turn, caused the rest of the problems.

To quote W8JI, in that link that NO6L provided about parasitic oscillations in a 3-500Z GG amp, "The only likely candidate for arcing is improper operation at or near the operating frequency."

I tend to believe Tom............

John
 
RE: The Big Step Up To 1.5 KW  
by N0CU on April 9, 2009 Mail this to a friend!
John: I am confused by your comments. I thought I was clear that I never suspected parasitic oscillations even though I was repeated told by others that they were clearly causing my arcing problems. I also gave the reasons why I did not suspect parasitic oscillations, and why I did suspect an over-voltage problem. In the end, I confirmed my suspicions regarding the over-voltage problem by linking the defective bandswitch to a condition similar to improperly loading the amp as the cause for the excessive voltages. I appologize for my poor communication skills.
Bill N0CU
 
RE: The Big Step Up To 1.5 KW  
by KB6QXM on April 9, 2009 Mail this to a friend!
AI2IA, I agree with you. It is usually lot cheaper and easier to reduce losses than to buy power and have all of the potential problems/expense that comes with an amplifer. Hardline, N connectors, trapless antenna designs, good SWR, low loss switches etc. etc. Eventually it is all about EIRP!! (Effective Incidental Radiated Power) for those who do not know the term.

It is the same analogy as one of my other hobbies-High performance cars. It is much cheaper to reduce weight than it is to build horsepower. Again, this is all about power/weight ratio.

Reduce your losses! Just look at the loss of "cheap" coax at even 30 Mhz. As we all should know in RF, there is no free lunch.
 
RE: The Big Step Up To 1.5 KW  
by WA1RNE on April 9, 2009 Mail this to a friend!

"I didn't need to ask for an ok to return the amp to the factory because Ameritron offered that option to me as soon as I described the problem to them."

-I don't enjoy disassembling hardware, packing it into three separate boxes, and then paying somewhere around $80-100 to ship it


>>> That's good, I was hoping they offered to do that, but return shipping should be at no charge.


It's disappointing to have to repack and return a new product but it's also a great feeling to get a new one a few days later - knowing that it's been put under the microscope and completely tested.


Obviously your decision....


...WA1RNE
 
RE: The Big Step Up To 1.5 KW  
by K1BXI on April 9, 2009 Mail this to a friend!
You are correct Bill, I see that those were the reasons others told you what were the cause of the problems you were having, which you rightly discounted. I can understand why you were confused by my reply.

I should have re read your article before replying. It was that last photo of the band switch from Rick Measures' that I believe he attributed to parasitic osculations that lead me astray.

Thanks for correcting me...........John

 
RE: The Big Step Up To 1.5 KW  
by W7ETA on April 9, 2009 Mail this to a friend!
I read your article and didn't see any mention of asking people if they approve your amplifier choice. Plus, I didn't see where you asked people to comment if they approved of your choice to have FUN tracking down the source of your problems and if they approved of you having FUN fixing the problems.

73
Bob

 
RE: The Big Step Up To 1.5 KW  
by AB7E on April 9, 2009 Mail this to a friend!
W7ETA,

N0CU submitted his article to a forum where comments of all types are invited and encouraged. Besides, nobody is second-guessing the enjoyment he might have had or the learning he might have gained. Instead, people are pointing out that he spent a lot of money on a poorly built amplifier, and then wrote several follow-up comments justifying the poor quality he received as a typical cost tradeoff.

If nobody disagreed with him, why would you ever expect anything to change? And why would you expect crummy quality to be limited to gear that can be repaired by the user? MFJ's lack of process control competency carries over to all of their other products ... check the reviews and you'll see the same comments over and over and over again. The only category of products made by MFJ I could find on eHam where their average rating isn't at least a full point below the average rating for all other manufacturers is clocks, and while most manufacturers get dinged for functional performance or customer service issues, MFJ gets consistently whacked for quality control defects.

Dave AB7E
 
RE: The Big Step Up To 1.5 KW  
by N0CU on April 9, 2009 Mail this to a friend!
John: Thanks for clearing up the confusion. I was really puzzled.
Bill N0CU
 
RE: The Big Step Up To 1.5 KW  
by N0CU on April 9, 2009 Mail this to a friend!
W7ETA: Bob, you are reading my mind. I should have stuck to my original decision to not mention mfg names so that the technical content of my article could be the focus of follow-on discussions. Oh well, I won't make that mistake again.
Bill N0CU
 
RE: The Big Step Up To 1.5 KW  
by N0CU on April 9, 2009 Mail this to a friend!
AB7E: I find it curious that you chose to exclude the data that rates Ameritron's high power amps. See my earlier post if you are really interested in the data set that quantitatively addresses the quality of that product line.
Bill N0CU
 
RE: The Big Step Up To 1.5 KW  
by AB7E on April 9, 2009 Mail this to a friend!

N0CU: "I find it curious that you chose to exclude the data that rates Ameritron's high power amps. See my earlier post if you are really interested in the data set that quantitatively addresses the quality of that product line. "


Ah, I see. The multiple defects you experienced with your unit must be an aberration, then ... unlikely to occur on a unit purchased by anyone else. I'm puzzled then, why you publicly advised everyone to consider buying a more expensive offering from a different manufacturer if they didn't feel they were up to the task of fixing a new one bought from MFJ/Ameritron.

For me, the type of defect is usually more telling than the percentage. The ones you experienced scream bad practices.

Dave AB7E
 
RE: The Big Step Up To 1.5 KW  
by W7ETA on April 9, 2009 Mail this to a friend!
I don't think it would have mattered if you hadn't mention who built the amp Bill.

I wonder what would have happened if you had mentioned the brand name of your soldering iron, brand name of your PL 259s, and brand name of coffee you drank while trouble shooting your amp?

My guess is that some people would tell you you are using the wrong soldering iron, wrong connectors and that you are spending too much for your coffee. :-) ANd then to boot, somebody will tell you shouldn't have married your wife.

73
Bob
 
RE: The Big Step Up To 1.5 KW  
by AB7E on April 9, 2009 Mail this to a friend!

This is hilarious ... it was just posted a few minutes ago.

http://www.eham.net/reviews/review/79781

Dave AB7E
 
RE: The Big Step Up To 1.5 KW  
by N7ZM on April 9, 2009 Mail this to a friend!
Boy if you rate Alpha Amps below Ameritron, your either blind, ignorant, and just don"t know what quality stands for. Your resoning doesn't make any sense.
Your ratings as you stated>>> unbelievable.....sounds like you have never owned or run any quality gear before.
RE:
ALPHA__87A________$6500___Rating = 4.7
ALPHA___89________$4000___Rating = 4.7
ALPHA_9500________$9000___Rating = 4.4

AMERITRON_AL-82___$2100___Rating = 4.8
AMERITRON_AL-1200_$2300___Rating = 4.8
AMERITRON_AL-1500_$2900___Rating = 4.8

Any more questions?

Bill N0CU
 
RE: The Big Step Up To 1.5 KW  
by N0CU on April 9, 2009 Mail this to a friend!
"Boy if you rate Alpha Amps below Ameritron, your either blind, ignorant, and just don"t know what quality stands for. Your resoning doesn't make any sense."

If you don't like these ratings, go complain to the folks that generated them- eHam. They aren't my ratings.
Bill N0CU
 
RE: The Big Step Up To 1.5 KW  
by NO6L on April 9, 2009 Mail this to a friend!
>by N0CU on April 9, 2009
>NO6L: Since you obviously didn't even read my article, I stopped reading your post after the first inaccurate criticism (regarding parasitic oscillations)!
N0CU

Then you also skipped reading the information the link I provided led to, as well. Seeing as how you didn't have the time to read it, I guess I can abridge it. Simply, "An amplifier tuned to HF is too inefficient at VHF to cause voltage excursions great enough to cause arcing". What causes arcing is not parasitics, it's improper loading, a faulty load, faulty engineering or in your case, faulty workmanship/damage. Anything else is "Old Wives Tales" and faulty conclusions from incomplete investigations. It's that simple.

If you're going to present information as an authority, then get the information right. Because a newcomer will take faulty information and cause more damage and get more grief than with correct.

And, if you can't take a little criticism, stop writing articles. God knows, everybody else, including me, has had their share of it.

de NO6L
/end of line
 
RE: The Big Step Up To 1.5 KW  
by N6AJR on April 9, 2009 Mail this to a friend!
I find MFJ and all of the associated companies fill a useful place in ham radio.



as for the quality control, it can be a problem, but they do honor their warrenty. I have several mfj amps here, an als 600, an AL 1200 and have had others like the 811 and 811H. Most have worked just fine and I have purchased mos of my gear used and they are still working. I also have some kenwood, Icom and Alpha amps and nary a problem with any of them.





My opinion is that Mr. Martin F. Jue serves a purpose in ham radio. several of his productions are ham radio ledgends. How many of you own a MFJ 259 B? or a MFJ 815b dual cross needle meter, or a MFJ 434 voice keyer or antenna switch in all their forms or the mfj remote antenn switch boxes and so on.





How about the mirage amps or the vectronics tuners, and so on. you can buy four 811 tubes matched from MFJ for $60 to $80 bucks.





MFJ Enterprizes make a ton of stuff for the shack that a lot of us could not afford to own otherwise.





first rule is to check it out when you get it and if its not right , either fix it or send it back for a repair or another new one.





If you buy one used and it is junk, thats a problem with the previous owner, not MFJ, but the will sell you the parts to repair it with, reguardless.





go on utube and look at some of the videos of the MFJ company iincluding their production lines. interesting stuff.




so is MFJ a bit less than perfect in quality control, yes.




does MFJ fill a big need for most all hams, again a resounding yes.




Just my opinion, but with some explaination.

now go build a fan dipole and work some DX
 
The Big Step Up To 1.5 KW  
by NX8J on April 9, 2009 Mail this to a friend!
What a story. The output tank bandswitch looks like it belongs in a receiver, not a transmitter.

A story about tires which has significance to yours:

Some years ago I worked for an international tire and rubber company in Ohio. A semi-trailer of our product arrived at a US based auto factory where Japanese cars were assembled. Upon opening the trailer, an empty discarded potato chip bag was discovered lying on the floor. The US subsidiary of a Japanese company rejected the entire lot. Reason given was (paraphrased) "If you don't care enough to remove trash from a valued customer's shipment, what other aspects of your business are lacking?". Our tires were safe and met spec. All they wanted to do was to send us a message. Received 40 over 9, thank you.

If I opened a new amplifier and found solder splash on the tank circuit, and other evidence of poor workmanship, I'd likely return the unit and think hard about buying from that manufacturer again. Did they not put the amp through final test? Did the test card show full output on all bands?

Thanks for the lucid article in eHam. There's nothing better than a detailed true-life recount of one's experiences (good or bad) with a new tool. Also, your article did not degenerate into code vs no code within three comments!
 
RE: The Big Step Up To 1.5 KW  
by G3LBS on April 10, 2009 Mail this to a friend!
I once found a wasp nest in an HF triband Yagi trap which was 90 ft above ground. Speaks for itself. Changed to homebrew quads.
W2/G3LBS
 
RE: The Big Step Up To 1.5 KW  
by K9IUQ on April 10, 2009 Mail this to a friend!
FWIW:

I bought an Ameritron Al-1500in April 24 2008.

I inspected the whole Amp after installing the Peter Dahl transformer. Good quality was observed, NOT overkill construction. NO loose parts or bad solder joints.

The amp has worked flawlessly in 6 contests and countless pileups for DX. The op at the other end does not notice I am not running a high dollar amp. 1500 watts Alpha is the same as 1500 watts anything else.

Last week I got a telephone call from someone at Ameritron telling me my warranty was up in 3 weeks and if I had any problems to let them know so it could be fixed under warranty. NO MANUFACTURER I have ever bought from has done this.

Note I am NOT a newbie, been using amps for 48 years..

Stan K9IUQ

 
The Big Step Up To 1.5 KW  
by KL7AI on April 10, 2009 Mail this to a friend!
Yes only one time I had problems,lost a PL259 due to bad solder joint. I have designed my station from the start to handle legal limit +++ power. Never had problems like that. I think you should haul your amplifier off to the the Ebay junk market. Try a TEN TEC, ACOM or ALPHA, and QRO makes a damn fine amp too!
 
RE: The Big Step Up To 1.5 KW  
by AB7E on April 10, 2009 Mail this to a friend!
W7ETA: "I wonder what would have happened if you had mentioned the brand name of your soldering iron, brand name of your PL 259s, and brand name of coffee you drank while trouble shooting your amp? "

Probably nothing, unless he also mentioned that they didn't work because of loose parts and missing solder.

Dave AB7E
 
The Big Step Up To 1.5 KW  
by WB4LFC on April 11, 2009 Mail this to a friend!
Whew! After reading all that I don't know if I am ready to make that next step.
 
The Big Step Up To 1.5 KW  
by WB4LFC on April 11, 2009 Mail this to a friend!
Whew! After reading all that I don't know if I am ready to make that next step.
 
RE: The Big Step Up To 1.5 KW  
by WB4LFC on April 11, 2009 Mail this to a friend!
Oops!
 
RE: The Big Step Up To 1.5 KW  
by N0CU on April 11, 2009 Mail this to a friend!
WB4LFC: Part of the reason I wrote this article was to help folks make a more informed decision before deciding to buy a big amp. I didn't mean to scare anyone off, but it is a big decision. Most experienced hams tend to recommend to start improvements with the antenna, then work your way to the amp as the last area for upgrading.
Bill N0CU
 
RE: The Big Step Up To 1.5 KW  
by KI4WCA on April 11, 2009 Mail this to a friend!
Excellent article and thank you.I have been considering a GS-35 based amp for 80.My design goal is only 600 watts, which may be too much for my location.If I built it, it would be capable of full legal limit which would be insane at my QTH.But the tubes heater requirements are so reasonable and it is so inexpensive, why not?I mention this because after the disaster you described the impetus to roll my own out of giant reliable components only increased!I am in no hurry, so I can take my time collecting the few things I need.Thank you again.
KI4WCA
 
RE: The Big Step Up To 1.5 KW  
by N2EY on April 12, 2009 Mail this to a friend!
Thanks for a great article that focused on your particular experience with that amp.

73 de Jim, N2EY
 
RE: The Big Step Up To 1.5 KW  
by HFRF on April 12, 2009 Mail this to a friend!
This is a very entertaining site but not very useful. In my opinion, this and most other sites contain nothing but nonsense. Its also entertaining to see how many people believe what they read when it comes from people they don't know, nothing is explained or proved with verifiable facts provided or linked to, nothing is illustrated,no attempt is made to make sense out of all those "prophetic" statements.

And for all the eHam celebrities that speak with apparent authority, I don't pay any attention to them either.

However, when somebody makes declarative statements, tries to at least briefly expain the basis, and maybe backs up their statements with some known and accepted real authority on a subject, I might conditionly accept it as plausible. I sure as hell wouldn't bet my life on it.
 
RE: The Big Step Up To 1.5 KW  
by K5PHW on April 12, 2009 Mail this to a friend!
Thanks for your input. When you post your call maybe you will be credible as well.


Have a nice day.
 
RE: The Big Step Up To 1.5 KW  
by HFRF on April 12, 2009 Mail this to a friend!
k5phw

You aren't credible at all even with your call. I will tell you what I want you to know about me not what you think you can manipulate from me. Got it smart mouth.
 
RE: The Big Step Up To 1.5 KW  
by K5PHW on April 12, 2009 Mail this to a friend!
I will tell you what I want you to know about me not what you think you can manipulate from me. Got it smart mouth.

Same deal here. But I don't hide my identity.


Have a nice day, douche bag.
 
RE: The Big Step Up To 1.5 KW  
by HFRF on April 12, 2009 Mail this to a friend!


k5phw-----------------

Another eHam child having a name calling snit but he probably needs just a diaper change.
 
RE: The Big Step Up To 1.5 KW  
by K5PHW on April 12, 2009 Mail this to a friend!
If I recall you started the name calling. Eh?


Have a nice day, whatever your name is.
Done with you now, but it was fun.
 
RE: The Big Step Up To 1.5 KW  
by W7ETA on April 12, 2009 Mail this to a friend!
Oh yea dog bone breath!?

Where is your proof “this and most other sites contain nothing but nonsense.”
Sounds like stray electrons from cold solder joints; sputum* from blown electrolytic capacitors; 126% modulation from a Galaxy 10 meter radio on channel 45.

*http://www.webmd.com/a-to-z-guides/sputum-cytology
 
RE: The Big Step Up To 1.5 KW  
by K5PHW on April 13, 2009 Mail this to a friend!
Charlie Chickenbander spouts off on a ham site and gets his toes stepped on. Story at eleven.
 
RE: The Big Step Up To 1.5 KW  
by W7ETA on April 14, 2009 Mail this to a friend!
Seems as if somebody doesn't like my sense of humor!

From:
"hams_suck" <hams_suck@fx.sytes.net>
Add sender to Contacts
To:
becketma@yahoo.com
Hi dog bone pin head.  Fun is coming.

Do you eat the diarrhea when barfing it up or do you just spit the diarrhea out and then barf more diarrhea.  How does it taste? 
Do you like the consistency?  I'll bet you spit it up in the air so you can get it splashed in your eyes coming down. 

What're you going to do now?  Fart.  Were going to have fun for a week or two.  I'm going to teach you a lesson you are not going to forget.
 
Talk about over-dramatizing  
by KASSY on April 14, 2009 Mail this to a friend!
So, you received a defective product, and instead of returning it for warranty work, you chose to make a school science fair project out of it.

And then, using commercially purchased antennas and balune (which every article on eham warns you not to do), you get the predicted results.

And this warranted an article?

It is a wonder that any ham ever manages to build a real contest station!

- k
 
RE: The Big Step Up To 1.5 KW  
by K5PHW on April 15, 2009 Mail this to a friend!
W7ETA: I received some hate mail as well.
I am really concerned about it. Not! LOL
 
RE: The Big Step Up To 1.5 KW  
by N7YA on April 15, 2009 Mail this to a friend!
Anytime someone tells you that you are going to "learn a lesson" or tries to scare you in anyway...via email...its neither a lesson nor scary.


Especially if they remain anonymous. LOL!!


Besides, those who post callsigns are easy to find, our addresses are listed...who is scared?
 
RE: The Big Step Up To 1.5 KW  
by WQ3X on April 16, 2009 Mail this to a friend!
Let me get this straight. You were sitting on some ham frequency running 1.5KW continuously into an antenna for 2 minutes? Real nice.

 
RE: The Big Step Up To 1.5 KW  
by KB0TXC on April 16, 2009 Mail this to a friend!
Dog bone breath???

References to eating um, well any way?????

Oh this is getting really intellectual, now isn't it?

Frankly, I was thinking about getting myself an Ameritron QRO, but thankfully someone wrote an article about their troubles with the unit, and now, I will think twice. I will at least want to see one in action before I spend money on one.

Maybe, I will not even QRO when I get on the HF bands. In a rather close spaced neighborhood, I really do not want to use too much RF power. Lots of little kids around here, and I have a ground mounted vertical. Even with a fenced back yard, I shudder at the thought of a wandering kid getting burned if they somehow got in and touched the antenna.

I love the nonsense that I often read here on e-ham. Even if several of the OFs here love to belittle me because I do not use code. What the hell, even the nastiest one uses a call sign, not a handle. The one little thing I wish e-ham would do is not allow anonymous posting...

And though I am no prude by any means imaginable, I could have gone all day without reading some really gross scatological references.

Best and 73

Joe KB0TXC

(BTW: e-mail threats are really stupid and childish. They can also lead to both civil and criminal action as well. Think twice before threatening anyone through an e-mail...)
 
RE: The Big Step Up To 1.5 KW  
by K9FON on April 17, 2009 Mail this to a friend!
There is more infighting among hams than any other gropu of people that I know.
 
RE: The Big Step Up To 1.5 KW  
by N7YA on April 17, 2009 Mail this to a friend!
I have noticed it more online, and definately more on eHam....i just dont hear it on the CW subbands as much, and i never see it in AES. Its mostly confined to 20 and 75 meter SSB, and online....THIS website is, by far, the grumpiest and most negative of them all. And ive been here for years.
 
RE: The Big Step Up To 1.5 KW  
by W7ETA on April 19, 2009 Mail this to a friend!
Down boy!
Down!
Not knowing CW is irrelevant.
You're just outta phase.
Get on the same side band as everyone else.
Dog Bone Breath is word play.
Some hams use Dog Bone insulators at end of wire antennas.

Bob




 
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