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1  eHam Forums / Elmers / RE: Wanted Heathkit Elmer on: March 24, 2013, 06:45:15 PM
Ralph

The majority of Heathkit work that one can do can be done with not much more than the original tools used to assemble the radio.

One would expect to have good soldering skills, adequate vision, and for repairs, knowledge of basic electronics ... the ability to read a schematic is critical.

Your work area should ideally be dedicated to the task, with adequate ventilation.  AC power, preferably locally switched, is a requirement, along with suitable lighting.  There should be a telephone handy for safety.

One would need the original radio assembly manual, preferably the same one use to build the rig, if it's still in readable condition.

A large-thermal-well type temperature controlled iron, such as a Weller WTCPx series (Curie-temp type) is wise to use, with a 700 degree tip, and a 80W conventional "American Beauty' type iron with conical tip is also handy for the times you need it.  And you will need it.  I would not talk you out of a 140W Weller type 8200 gun, either.

You will want some fresh, rosin core solder.  There are many types out there, but, good old Kester #44 is your best bet.  0.062" size for vintage Heath gear.

You will need a desoldering tool and the skill to use it.  The ONLY useful tool in this case is the Edsyn model DS-017 and you'll hear plenty of other advice regarding such devices.  Ignore these well meaning yet erroneous suggestions.

You'll be doing some electromechanical disassembly, too, so a good digital camera with macro mode is almost a must-have.  A variety of simple yet high quality hand tools will be needed and believe it or not, we still make these in this country... and they're often available at the major home improvement stores in many cases.

Lastly, an RF signal generator, wattmeter, RF dummy load, bench grade digital multimeter, and an oscilloscope will round out your basic Heathkit restoration bench.  If / when you need more than this, you'll have to resort to getting help from others anyway, and they can arrive to work in your new well-appointed work area for the best of camaraderie and learning.

73  Steve KZ1X
2  eHam Forums / CW / RE: I need a new keyer with 8 memories: suggestions? on: February 18, 2013, 08:24:08 PM
I know you said 8 memories. 
As was posted above, I am mighty curious what one would put in them... but then I have 8 memories on my logger program driving my WK USB.
I do use the various memories for multiple exchanges.

Anyway, this is a 6 memory button sleeper:

http://www.hamgadgets.com/index.php?main_page=product_info&products_id=106

It is K1EL compatible...
3  eHam Forums / Licensing / RE: Just wondering... on: January 31, 2013, 07:54:54 PM
Well, when you lived in NJ back in the 1980s, you had a Tech class ticket, which means you passed at least 5 WPM.
4  eHam Forums / VHF / UHF / RE: Coax length for 5w HT use to roof mount antenna? on: January 28, 2013, 07:16:34 PM
If you buy a commercially available amateur dual band vertical antenna, to 'match' the handheld you have, you won't need to adjust it nor use a 'tuner' in line.  Indeed, most of these antennas offer no means to make any adjustments, anyway.

However, the type of feedline you use, and its length, are of great importance.

At the frequencies you are using, typical coaxial cable is VERY lossy, and adding even a 50 foot section of certain types of it is just like eliminating the antenna.  

You should do an internet search for "coax loss" to learn more about this phenomenon.

Cables that exhibit low enough loss to run 75-100 feet at VHF and UHF frequencies will be relatively costly, indeed they can cost more than your radio.
You may find that running the antenna on the roof is not economically feasible.

Fortunately, you have other options, such as a small end-mount beam mounted on a short mast just outside the basement.  I would seek the the help of a knowledgeable ham in your immediate area, who can visit you and offer guidance and suggestions.  I used to live in NJ but not near where you are, however, there are certainly a lot of hams in the country's most densely populated state, and especially in a tech-rich area like where you are, you'll find plenty of local help.  For example ... try these guys, they are truly top-tier:

http://www.jsars.org/
5  eHam Forums / Elmers / RE: HW8 receiving broadcast interference. on: January 26, 2013, 05:47:39 PM
it wasn't WYFR by any chance?  In Maitland, they're still a good bit away from you to create such an overload condition.

Would be helpful to know what you were hearing.  For example, a malfunctioning local AM station could cause this problem.
6  eHam Forums / Elmers / RE: Help identify this 900 MHz antenna and its pattern on: January 26, 2013, 05:40:34 PM
At less than a wavelength away from this type of antenna, multipath will predominate in most every environment you'd use this in.  So, there won't be any discernible pattern. 

Check out me in a video of a system at 900 MHz designed to work differently than this, and see how large the antennas have to be to have realized indoor patterns:

http://www.wral.com/lifestyles/healthteam/video/8930431/#/vid8930431
7  eHam Forums / Mobile Ham / RE: Best Hand Held HF SSB Receiver? on: December 31, 2012, 05:57:26 AM
The R20 is truly a terrific unit -- and for more reasons and uses than you have indicated. 
Not cheap, though.
I had two at a previous employer and really miss having access to them.
I used them daily for years.
8  eHam Forums / Elmers / RE: Preamplifier limitations on: December 28, 2012, 10:31:44 PM
Let's say a common small signal amplifier (useable as a preamp) is set up in a lab, connected to a calibrated good quality RF sinewave signal generator.  

The amplifier is configured for 50 ohms impedance in and out, matching the specs of the signal generator.

The gain of the preamp is set to be 20 dB.  You power up the generator and the amplifier.

The signal generator is set to put out a signal of -70 dBm; in this example ... by the way, this is a tiny voltage ...  0.0000707 VRMS !  (70.7 microvolts) but would be a fairly strong signal for most receivers.

The output of the lab example preamp is put into a spectrum analyzer, also having a 50 ohm impedance.

The analyzer shows a 20 dB stronger signal ... -50 dBm.  Voltage-wise, this is now 0.000707 V RMS.  Good; we've confirmed the preamp is working to spec.  In the lab, anyway.

You can see where this is going ... if you kept adding amplifier stages, wouldn't you eventually be able to generate tremendous amounts of power?  

Well, perhaps, but you would also not be talking about small-signal amplifiers anymore!  Power levels, noise, distortion, and linearity issues become readily apparent variables to deal with ... quickly.

In the lab example, it may or may not be true that adding another identical preamp in series with the first one would result in a signal of -30 dBm.  

There would be many factors to consider, beyond the scope of this simple example.  Amplifiers of this sort are definitely NOT created equal!

And, in the real world, a preamplifier generally doesn't have the luxury of amplifying just one signal like the one in the lab example above.  It is usually faced with seeing 'all' the radio signals an antenna might supply to it.  This is often a complex stew of RF energy and how the amplifier responds to such is often the subject of a good bit of RF engineering.

You asked about raising the noise floor.  That's an interesting additional discussion.  Question:  wouldn't a suitable antenna preamplifier, without any input filtering, not raise the entirety of input energy by the same amount, whether that energy was desired signal or noise?
9  eHam Forums / RFI / EMI / RE: BAD RFI.... on: December 28, 2012, 07:23:42 PM

 And that is my main problem- building a directional micro mini 80 meter antenna. Something that is not 70 ft long. I was hoping someone who is knowledgeable with "DFing" might have a simple design I could home brew.



You could scale this down to the frequency range you need. 

http://www.k3zxl.com/Loop.htm


The web instructions for this antenna are EXCELLENT ... may be the best I've ever seen, anywhere.
Dan, if you are reading this, bravo and thanks for documenting your test antenna so well.

The ideal radio I have found for DF-ing is an Icom R-20.  If you have or can find one to borrow, terrific.  Other rigs will do, of course...

Take two 90 degree radial readings to your expected target and draw the lines on a scaled local map.  Then, go back and add a third line from some other angle ... and you're there.

gl

Steve KZ1X
10  eHam Forums / CW / RE: Fun word rhymes to send with cw? on: December 23, 2012, 09:21:27 AM
Ben's best bent wire.

(Skip the apostrophe and the interword spacing.)
11  eHam Forums / Elmers / RE: What factors differentiate amateur with others? on: December 19, 2012, 10:32:56 PM
Are you in the US?

http://www.arrl.org/files/file/Regulatory/Part%2097%20-%2004-28-2011.pdf

See the very first section.  You are never ever allowed to make money with your ham station, ever.

We're amateurs. 

Professionals get paid to use their radios, and, we are specifically prohibited.

Same basic rule exists in every country where amateur radio exists.

Also ...
ยง 97.117 International communications.
"Transmissions to a different country, where permitted, shall be limited to communications incidental to the purposes of the amateur service and to remarks of a personal character."

We're the world's only hobby regulated by the UN (ITU).

12  eHam Forums / RFI / EMI / RE: RDI-resistant USB-RS232 interface on: November 03, 2012, 10:37:31 PM
The bane of many hams' existence are the little cheapie far-east USB to serial converters.

There are good ones, made by the Austin based firm once known as InsideOut Networks, and now owned by Digi (Minneapolis).

The product line is called Edgeport.

If you get one (most of them are multiport) surplus, they are a screaming good deal.  Of course, the word is out about them so when they show up on ebay and etc. they go, FAST.

New, they are priced for the professionals that use them, who would never THINK about using the cheapies.

My K2, K3, P3, KPA500, M2 RC2800PX, TenTec RX320D, LP-100 wattmeter, and home automation system are ALL connected via serial RS232 ports to ONE Edgeport/8 here.  No RFI, not a peep, never a problem, no COM port issues, no driver weirdness, nothing.  Ever.
13  eHam Forums / Elmers / RE: Right angle pl-259 connector on: October 29, 2012, 02:54:07 PM
These connectors go together much like a compression N or BNC do, except that instead of soldering the center conductor into a tip, you pre-trim it to solder in the access hole, then snap the cover over that.

In general the idea is that the shield presses against the inner flange after having been dressed over the sleeve washer, the end of which is pressed in via the compression core.  However there are  variants, and this connector is a bit different than the usual we have here in North America.

If you have not previously installed the similar conventional connectors, I will try to help anyway but some tasks are best taught in person, not with words over the internet.  I do not know your skill level, experience, what sorts of tools you have, your soldering ability, what cable you are using, etc., and all of these are important variables.

Please write back and give me some idea of what the situation is, so that I may best assist.

Just for starters, the parts likely assemble in this order:

Large threaded nut
large thin washer
compression core (rubber piece)

Then there is the issue of the inside of the fitting, can you take a picture that shows this, with the focus on the inner flange that terminates the assembly shaft?  Won't be an easy picture to take.
14  eHam Forums / Elmers / RE: Best dual-band mobile antenna on: October 29, 2012, 11:53:08 AM
Austin 500C

http://www.eham.net/reviews/detail/2771

15  eHam Forums / CW / RE: CW Keying on: October 07, 2012, 09:09:33 PM
Do you have any conventional, that is to say, non-noise-cancelling headphones?

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