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Author Topic: FU728F & 4CX1500B Question  (Read 29594 times)
VK2UW
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« Reply #15 on: April 05, 2013, 04:47:53 AM »

Not even worthy of a reply, how senseless some people are, if you could afford one why would your be worried plus your heater and monthly bath would most likely cost you more in "G" land. Shocked Grin
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Every Man's Transceiver Relies On Nothing!.  When connected to
an Emtron SP amplifier.

Looking for a High Quality Amplifier?

If you need the best? then buy the best! Be confident and in control of
your station at all times.
check link supplied for your needs in "HF" Amplifiers.
ZENKI
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Posts: 927




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« Reply #16 on: April 13, 2013, 08:30:07 PM »

 FU728 has lousy IMD performance when compared to the 4cx1500B. The 4cx1500B was designed for linear SSB service and there is no Chinese or Russian tube that can beat the IMD performance of the 4cx1500.

Power for the sake  of powers sake without considering the IMD performance is best left to the CB band.

Driving a pair FU7828's to  the 5kw PEP output level is not acceptable practice since the IMD performance is so poor.

If you need 5kw PEP output for your VK license use a 3cx3000A7 which a linear tube designed for SSB linear service. The IMD performance is -44dbc more that 50% better than a pair of FU728's

When running output powers  of 5kw you certainly do want to make sure your tube and transmitter meets ITU standards. Unfortunately most ham equipment splatters as bad  as most CB equipment. Using ham transmitters
with poor IMD performance tubes like the FU728 is would be disaster for the ham bands. Very few hams own a spectrum analyzer  or SDR receiver that can monitor the IMD performance of their transmissions.

Practices such as ESSB and not using RF speech processing  with ham transceivers and when used with transceivers that have ALC design issues can make a mess of the ham bands.

To run the high 5kw power that you mention unfortunately most hams dont have the technical skills or ability to do so in a manner that is considered professional and considerate of other users of the ham bands.



About the FU-728F tetrode, the tube is bigger in height than the 4cx1500b and has far better cooling and this also allows for a higher PEP rating than the older Eimac 4cx1500B, and has also been tried and tested in these Emtron Amplifiers as the bases are the "4CX1500B bases", so no need to change the bases if you want to use 4CX1500B tubes but you will notice the PEP rating will drop quite dramatically.

Please note:  Yes these are the "4CX1500B Bases" not the FU-728F type so no need to change if using either.

Power using the Eimac 4cx1500B will be very noticeable as it is not in 10's of watts that it drops, it is in 100's of watts using the older Eimac 4CX1500B.

The FU-728F is far superior and a higher output than the older Eimac 4cx1500B and is more readily available but don't buy on eBay.

Emtron purchase from the factory direct re the FU-728F and will supply all Emtron owners if needed in the future.

If you check the all new Emtron Website and read up on the ranges and read about the FU-728F and the equivalent 4CX-1500B you will see that it plainly tells you that these tubes are interchangeable and what changes needed.

Here is an example from the DX-3SP range and take note on the FU-728F and 4CX1500B: 

The "Big Gun" is getting even bigger, with the new DX-3SP! With over 4000 Watts CW and more then 4500 Watts SSB, this QRO muscle amp is not a joke! It is an amplifier with gravitas capable of satisfying the serious and most fastidious station operator. All specifications and features, except output power, are the same all throughout the Emtron amplifier product range, and the DX-3SP comes complete with QSK module as standard. The design deploys two durable FU-728F tubes (improved Chinese mil-version of the 4CX1500B) in parallel, with a total plate dissipation of 3000 Watts, comfortably delivering the expected output power and durability. These robust FU728F tubes are manufactured in present production and are available directly from the manufacturer, or from Emtron, exclusively for Emtron amplifier owners. We believe that this new DX-3SP is physically the smallest 4000 Watt desktop RF amplifier on the market today, and the most popular as well.

Please note: This new DX-3SP comes with two FU-728B tubes, which are directly interchangeable with Eimac 4CX1500B tubes! Only the filament tap on the transformer must be changed from 9 volt to 6 volt, if Eimac tubes are used!


The above PEP rating is very conservative as tested into a Dummy Load of 50ohms and showing 5000watts yes 5000watts PEP.

So this Emtron DX-3SP is no slouch comparing to other brands that are much dearer and not as sophisticated nor with the same Engineering and Safety features as the emtron range of amplifiers.

Even the DX-2SP tested into a Dummy load of 50ohms gives a whopping 3000watts PEP.

I have been building my own 50ohm Dummy Loads for quite some time using Carborundum Resistors. The later one using 3 of 150ohm x 3000watts each with 450cub Mt's of forced air cooling, with a total of handling 9000watts of power. I have tested the above to the maximum into these loads.

Others using these High Power Emtron Amplifiers can agree with me on what you can use and do with these Superb Amplifiers that nobody and that is nobody has been able to match in Quality / Engineering / Safety Features along with Support for these highly sought after amplifiers.

I hope this sorts out the issue that some have about the different basses for the FU-728F and the Eimac 4CX1500B.

Check the all new Emtron Website for the latest information and all the new features:
http://www.emtron.com.au/

I welcome others inputs confirming what I have just written.

73's Chris
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KC4MOP
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Posts: 731




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« Reply #17 on: April 27, 2013, 03:52:50 AM »

Think of the electricity bill with that DX3 SP amplifier!

You might be able to afford to buy it, but could you afford to run it?
I wouldn't worry about electricity bill.
If it's used as a Ham radio amp it is not a worry. The usual rag chew QSO (SSB) or CW EVEN on the AM mode!
If used as a bootleg pirate radio station then there would be concern.
I am really impressed with the Emtron design and build of the DX-3SP. I sent a request for price and shipping to USA.
Fred
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ZL4IV
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Posts: 44




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« Reply #18 on: June 07, 2013, 03:52:32 AM »

The DX-3sp uses 300 watts on idle. Mine will do 5kw pep into a dummy load and pulls just under 40A at 232v. As of writing there are about 900 Emtron amps sold world wide.
I service these amps and know them inside out. Most of the problems are ham induced like pulling on wires instead of the connector when shipping the amp and having to remove the heavy transformer.
It's quite interesting to read the comments of those that never owned an Emtron. I have owned Alpha's and many others etc. What I do like now what Emtron have done is made the range parts compatible. They were almost 100% compatible before but with different tubes.
Then there is my factory modified DX-3 with the GU78B. Everything from 40m down is DX-4, modified for a North American contest station.
It would seem that once you get past the DX-2sp capabilities the average Ham or know it all gets out of his knowledge ability of real QRO amps. How could it be any different if they have never owned one. My DX-3sp came from a ham that traded down, had bit off more than he could chew. BTW, they run just fine at the legal limit, just like the Bugatti Veyron.

ZL4IV
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ZENKI
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Posts: 927




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« Reply #19 on: June 07, 2013, 04:37:00 PM »

The average ham who needs this kind of power should spend more on his antenna system.  If you cant be heard with 1kw,  4 or 5kw is not going to make your life  better if you have a crap antenna. So the typical QRO ham
has poor antennas and  a big amplifier. Its worst when you in a big city and cant even hear the stations calling you. We all know these alligator stations.

Now Joe average ham can buy a  your DX3SP, but Joe average ham cant select a transceiver that has good IMD specifications and select one that does not have a ALC issue that causes excessive tetrode splatter.
Just about every tetrode amplifier user with a Icom or Yaesu  transceiver has a filthy signal because of the poor ALC design. This is before we start talking about the ones who cant understand what the implications of using a tetrode amplifier is. Issues like understanding that grid current causes splatter.

For these reasons I would not  recommend a high power tetrode of any brand to the average ham. If they do want to play with illegal power use a decent tube like the 3cx3000 that wont harm other  ham band users.
Playing with such high power takes serious station design and its very important that one have a good station monitoring system in place. If you dont have a second receiver monitoring your station you will soon be run off
the air because of your bad splattering station. 

As typical those who promote these illegal QRO amplifiers never provide any expertise in their manuals  about running a clean station. They just assume that every ham is broadcast SSB expert with years of training.
I have never ever seen any amplifier manual suggest that after you tune your amplifier that you check your transmission with a second receiver. They should suggest that amplifiers users who run QRO should run  their amplifiers with a good SDR receiver monitoring their output at a signal  level of 40db over S9. Of coarse broadcast stations do this routinely, yet here again  you have illegal equipment being peddled at hams by people who have no consideration  or technical understanding on the importance of a issue like IMD splatter.  Hams are supposed to be  technical experimenters who eat, drink and sleep with technical issues like IMD and splatter.  All  we see here again
is endless  hyperbola by QRO CB lids who have no idea how to run the equipment they sell and they expect other ham users to put up with the garbage signals from illegal QRO equipment.

This is the problem with consumerism, you put equipment in the hands of people who dont know how to use it. Hams who at least build  their own homebrew amplifiers know what they are doing.
Its just unfortunate  that many hams who buy this QRO equipment are  poorly technically educated lids who have very little consideration of other users of the bands. If they all produced clean signals nobody would complain so much.

If you want a clean signal use a triode amplifier.


The DX-3sp uses 300 watts on idle. Mine will do 5kw pep into a dummy load and pulls just under 40A at 232v. As of writing there are about 900 Emtron amps sold world wide.
I service these amps and know them inside out. Most of the problems are ham induced like pulling on wires instead of the connector when shipping the amp and having to remove the heavy transformer.
It's quite interesting to read the comments of those that never owned an Emtron. I have owned Alpha's and many others etc. What I do like now what Emtron have done is made the range parts compatible. They were almost 100% compatible before but with different tubes.
Then there is my factory modified DX-3 with the GU78B. Everything from 40m down is DX-4, modified for a North American contest station.
It would seem that once you get past the DX-2sp capabilities the average Ham or know it all gets out of his knowledge ability of real QRO amps. How could it be any different if they have never owned one. My DX-3sp came from a ham that traded down, had bit off more than he could chew. BTW, they run just fine at the legal limit, just like the Bugatti Veyron.

ZL4IV

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AB4D
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« Reply #20 on: June 07, 2013, 04:53:36 PM »

The DX-3sp uses 300 watts on idle. Mine will do 5kw pep into a dummy load and pulls just under 40A at 232v. As of writing there are about 900 Emtron amps sold world wide.
I service these amps and know them inside out. Most of the problems are ham induced like pulling on wires instead of the connector when shipping the amp and having to remove the heavy transformer.
It's quite interesting to read the comments of those that never owned an Emtron. I have owned Alpha's and many others etc. What I do like now what Emtron have done is made the range parts compatible. They were almost 100% compatible before but with different tubes.
Then there is my factory modified DX-3 with the GU78B. Everything from 40m down is DX-4, modified for a North American contest station.
It would seem that once you get past the DX-2sp capabilities the average Ham or know it all gets out of his knowledge ability of real QRO amps. How could it be any different if they have never owned one. My DX-3sp came from a ham that traded down, had bit off more than he could chew. BTW, they run just fine at the legal limit, just like the Bugatti Veyron.

ZL4IV


Sir, be careful what you say about your amplifier in ZL land.  One of your fellow country men was fined a while ago for just owning an amplifier with the capability to exceed legal limit.  He had a video showing him transmitting into a dummy load at 3100 watts.

http://www.arrl.org/news/new-zealand-s-radio-spectrum-management-cites-ham-for-transmitting-3100-w

73
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ZL4IV
Member

Posts: 44




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« Reply #21 on: June 07, 2013, 11:00:54 PM »

ZENKI is quite right, antenna system is much better investment. I don't use my amps, I O/H them and sell them on. Why? Because I built my own tower and antenna system so I could hear as well as I could be heard. On 20m I have 4 elements on a 33 foot boom, 1 3/8 non-tapered elements supported internally. On 17m, 3 element 1 1/4 non-tapered elements. 12m, 3 element 1 inch non-tapered elements. All interdependent LDF 5-50 hardline switched in the shack. I often work OE6MBG with his 100mw and my rig will only go to down 5w. Can hear a pin drop, a fan running in the shack drives me crazy. The discussion was about the tube type. Another example, the 4CX1600B was ratted at 1600w for the FCC approval in amps for the ham market in the US but it is far more of a tube than that. The FU728F is also used in the DX-1sp with a lower B+, I think that's a 1kw amp. They do tell me you need power on 160m, don't think I could keep anything up in the air for that band in our winds.

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VK2UW
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« Reply #22 on: June 15, 2013, 02:49:39 AM »

It is easy to see the jealous types and the difference between those and the knowledgeable.

Emtron and that is all amplifiers built by Emona Electronics  (Commercial Engineering Manufacturer) have that many safety features for the best IMD in any amplifier are not included in other brands even Alpha / Acom nor OM.

Emtron have covered every safety feature.
 
These amplifiers have the best IMD specs of any amplifiers ever manufactured.

It is easy to say things but to prove what you are saying without the proper knowledge is dangerous.

I am a member of other amplifier groups, and in those groups are ones that want FCC approval, then want the supplier to supply them buyers in NA with the information to make them illegal.

Now tell me who is doing it right.

Safety features in the emtron range leave those other brands standing still and back in the dark ages.
All those manufacturers are doing is catering for the "BLACK BOX OPERATORS" or "Lids" as you say.

They the "Black Box Operators" or "Lids" are more than catered for with the manufacturers that are cutting costs for the lack of safety features and over priced.

If you do not know what these are then it might pay for you to enquire or read the specs of these Engineering Designed Amplifiers to the highest level ever.
Logged

Every Man's Transceiver Relies On Nothing!.  When connected to
an Emtron SP amplifier.

Looking for a High Quality Amplifier?

If you need the best? then buy the best! Be confident and in control of
your station at all times.
check link supplied for your needs in "HF" Amplifiers.
G3RZP
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Posts: 4502




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« Reply #23 on: June 16, 2013, 09:34:43 AM »

Have a financial interest in the company?
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VK2UW
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Posts: 13


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« Reply #24 on: June 16, 2013, 03:00:17 PM »

Re:  "Have a financial interest in the company?"

Not is any way, I am just one very happy customer. If every Commercial Manufacturer be it Radio or Amplifiers or for that matter in any products supported the products that they build / supply / service like Emona or Emtron do you to would feel the need to support them.
Especially when persons have or don't own or never have any products and put up lies or un truths about the products they Emona / Emtron manufacture, I/We are entitled to give our input as to dealings that I/We have had and support those that support our Hobby.

I hope that covers what you were asking G3RZP.

 
« Last Edit: June 16, 2013, 03:03:06 PM by VK2UW » Logged

Every Man's Transceiver Relies On Nothing!.  When connected to
an Emtron SP amplifier.

Looking for a High Quality Amplifier?

If you need the best? then buy the best! Be confident and in control of
your station at all times.
check link supplied for your needs in "HF" Amplifiers.
VK2UW
Member

Posts: 13


WWW

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« Reply #25 on: June 16, 2013, 04:23:52 PM »

To AB4D,
             you all seem to be picking on Emtron or owners of such for leading the way re Tetrodes etc from China.
Emtron have always been the leader in Tetrodes and have broken the water so as to speak for other Manufacturers to follow, even Alpha are using Chinese tubes as you have high lighted in your frustration with your Alpha 9500 and supposed disappointment of such.

 Cut and pasted from AD4B site:
("I feel the same way as most in the group. I also feel very slighted that their business decision to only credit some, but not all, did not include everyone who shelled out 9 or 10+ thousand dollars to purchase a 9500 which now costs less than 8K. I believe that we all knew that the price for the 9500 was inflated (more expensive than any other manufacturer), but in our hearts we felt that we also were supporting an American Company, an Icon to the U.S. amateur radio market. I certainly did not want to see Alpha go away forever. Believe me when I say that the final decision of whether to purchase an Alpha or an Acom came down to the country of manufacture and the fact that Alpha was using a U.S. made tube (more on that later).

My amplifier arrived looking as though the bottom rear corner was dragged across a concrete floor, but I accepted the factory damage without a word to Alpha, I did not want to wait another 4 long months for a different amplifier. Then, during the fan modification I discovered that the tube in my amplifier was a Chinese made 8877, instead of an Eimac. This change was done without my knowledge or consent, and was not consistent with the advertisement of the amplifier when I placed my order. It took me 6 months to resolve the tube issue with Molly. Then the blower fan became noisy, Alpha could not even supply a replacement, I had to send the fan back so it could be rebuilt. Now Alpha has devalued my amplifier further by dropping the price 1K+. Yes I am more than a little irritated about the whole experience. Will I ever purchase another amplifier or product from Alpha. At this point I can't say whether I will or not, a credit certainly would have wowed me. I can only assume by Alpha's actions that those of us who truly supported Alpha early on were deemed not to be worthy of Alpha's "gratitude and thanks." ).


Also on your site you say that you had an issue with the Chinese made 8877 but after swapping tubes and then replacing the original from China you state that it may have been a seating issue.


It goes to show that others are ready to knock other manufactures in the products that they use when a component issue can be a failure.
Manufacturers can only use what suppliers issue and depend on the quality there of.  A product failure can occur with the best of products be it Radio . Amplifiers or even Motor Vehicles. This is one reason why we do see a recall for a replacement of a specific item.
These issues are out of Manufacturers hands as they can only depend on the quality supplied.

Rudi from Emtron is and has always been in the foreground in trying to build in protection to every part of his product's because of this issue. Emtron have the most protection of any amplifier ever manufactured and still finding even more to date.

Not one other amplifier manufacturer apart from Emtron can say this nor be as proud of such safety protection in every way.
This is not only good for us in finding an issue if one does ever occur, but in the expensive outlay of replacing parts un necessary due to a fault.

Plus Emtron do also have a "Yahoo Group" and in that group there is nothing to say do not advertise any problems or issues on the group, or contact Rudi direct.
Rudi has and is always out in the open if ever an issue does come up, as this not only allows others input to the issue but in a resolve of the problem.

We Australian's are just as proud of our local manufactures as you in the USA, so let's build a bridge and stop all these supposed lies about other manufacturers.
Logged

Every Man's Transceiver Relies On Nothing!.  When connected to
an Emtron SP amplifier.

Looking for a High Quality Amplifier?

If you need the best? then buy the best! Be confident and in control of
your station at all times.
check link supplied for your needs in "HF" Amplifiers.
ZL1BBW
Member

Posts: 371




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« Reply #26 on: June 16, 2013, 05:39:08 PM »

This seems to have gone from a reasonable question, to an advertising spiel.  Out of interest read the following link, that may raise even more questions?/

https://groups.google.com/forum/#!msg/aus.radio.amateur.misc/1NsBNSrIiKU/rKMpfWgTtUEJ
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ex MN Radio Officer, Portishead Radio GKA, BT Radio Amateur Morse Tester.  Licensed as G3YCP ZL1DAB, now taken over my father (sk) call as ZL1BBW.
VK2UW
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« Reply #27 on: June 16, 2013, 06:46:21 PM »

ZL1BBW,
            have a look at all the fictitious email addresses and others names that these big brave so called persons or our latest introduction to Ham Radio that the changes have allowed.

Not one of them are man enough to stand up for themselves.

It is just like one of those on that group, that rubbished Emtron products without ever owning or using such, and spread rumours and lies on the internet about Emtron, he then turns cheek and wanted to purchase one of the all new Emtron DX-1D amplifiers at what he said was "MATES" rates.

Emona Board told him that he would be better looking at some other brand.

I think he still has his Ameritron 811H that costs only $30.00US to assemble.
He has not been on air for awhile as his splatter from over driving his now fitted Taylor 572 tubes in the poor old Ameritron that was only built to take those 811 tubes.
The poor old power supply in that thing is slowly dying but great news to all those that can now work within 60kc's each side of him.

Also on that group, isn't it funny about that so called 11mts especially when those sent in false complaints to the ACMA were proved wrong after me being visited and monitored to get a clean bill of health.

Non of my equipment is nor has ever been operated illegally or otherwise.

This is one reason why I can reply to this forum without being frightened of threats from others.

I hope this does clear up some of the garbage on the net being placed by children if you could call them that or put them in that class. Especially those so jealous of what I have and do support.

It is all good to seeing these Bullies starting to be come known and now begging.

They to also forget that Emtron are also keeping prices at a level that we Hams can afford without over mortgage of your property to own such.
Logged

Every Man's Transceiver Relies On Nothing!.  When connected to
an Emtron SP amplifier.

Looking for a High Quality Amplifier?

If you need the best? then buy the best! Be confident and in control of
your station at all times.
check link supplied for your needs in "HF" Amplifiers.
ZL1BBW
Member

Posts: 371




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« Reply #28 on: June 16, 2013, 07:28:40 PM »

VK2UW.. Thanks for the input.  For myself, the very idea of purchasing a commercial amp is heinous, there are enough well researched designs that any reasonably capable person should be able to build an amplifier.

Having had the opportunity to discuss various amplifier designs, I do recognise that there are some green eyed monsters.  But having said that, there is sufficient evidence out there to question the merits of Emtron amps, and having discussed this with a well versed tech, I personally would not touch one with a barge pole.

Anyway, lets get the popcorn and sit back and watch this thread.

Oh and to back up my opinions, I have been a licensed amateur for nearly 50 years, have built several large amps, operated and repaired commercial multi kw transmitters.
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ex MN Radio Officer, Portishead Radio GKA, BT Radio Amateur Morse Tester.  Licensed as G3YCP ZL1DAB, now taken over my father (sk) call as ZL1BBW.
VK2UW
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« Reply #29 on: June 16, 2013, 10:01:05 PM »

ZL1BBW,
             thanks for the reply and response, as I always say everyone to their own.
Re that link with the ZL station on you tube, this was also tried by those on that group making out is was me that initiated a site with me supposedly running either 3 or 4kw.

But the ACMA seen through the idiot factor that is behind this lot.
That was put up just after I had the 1st false visit from the ACMA.

Oh on that visit the ACMA Inspector was very impressed at my Homebrew Dummy Loads and the test we did with both the ACMA's on mine.
Even one of these idiots does use an Emtron DX- early model and is trying to tell all that he is using a Collins amplifier with 811 tubes.
You don't have to be an expert to hear and tell the difference between those two on air.
Then the same person tells an "F" call that his Gap Vertical has worked stations both on 40 / 80mts using only 100watts also on the DX window on 80mts all over the world longer and louder than any ZL/VK any time of the day or night. Then to top it off tells him that on 20mts it will even out do mono band beams of any size stacked or otherwise using only his 100watts. This was only 2 nights ago on 80mts.

He is also the same person that Rudi from Emtron had to phone for spreading lies about Emtron in the past

Rudi is also yet to catch up with a VK3 mate of the above, (Now working for the WIA) whom he has left messages for to contact him along with other Technical persons also passing that on to him but still no contact. I wonder why?.

They don't have the proof to support the lies being told.

I can if needed put names and calls to each and everyone for you if needed.

Thanks
Chris

 
Logged

Every Man's Transceiver Relies On Nothing!.  When connected to
an Emtron SP amplifier.

Looking for a High Quality Amplifier?

If you need the best? then buy the best! Be confident and in control of
your station at all times.
check link supplied for your needs in "HF" Amplifiers.
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