Has anyone had any experience with these Heathkit Stereo Generators? I have some old tuners and would like to touch-up the multiplex section and was wondering if this generator was any good? <P>Thanks in advance,<P>------------------<BR>Don

I've been trying to snag one of these and/or a Heath FM Deviation meter (IM-4180), but they seem to go way out of my price range (on eBay).<P>I wonder how much parts would cost to replicate these using the schematic and manuals? Yet another homebrew project.<P>Mike Yancey<BR>Dallas, Texas<P>------------------<BR> <A HREF="http://www.mikeyancey.com" TARGET=_blank>http://www.mikeyancey.com</A>

Mike,<P>I know what you mean. I have been bidding on them for a couple of years only to see them go to about $100. What really makes me mad is to find out that one went for $29 BIN on eBay and I missed it! I did get the construction manual so when I get a chance, I will scan it and offer it to the BAMA site since they don't have one.<P>------------------<BR>Don

> What really makes me mad is to find out that one went for $29 ...<P>I hate when that happens. I have it bookmarked, I get busy (you know, sleep or something...). I actually looked back and recent buys of IM-4180's are maybe $65 or so. Last IG-37 was 69.58 (a buy it now for over $100 didn't go). I guess that's not too very much, but I bet if *I* bid, it'll get out of hand. <BR> <A HREF="http://www.tech-systems-labs.com/heathkit.htm" TARGET=_blank>http://www.tech-systems-labs.com/heathkit.htm</A> just posted an IG-37 manual. <P>Mike Y.<P>------------------<BR> <A HREF="http://www.mikeyancey.com" TARGET=_blank>http://www.mikeyancey.com</A>

Hi Mike,<P>Yeah, I hate it too. Wow, just when I get a good copy of the manual, ($20 including shipping, BIN) one becomes available on the web for free. Oh well, I will still scan it PDF and see if BAMA wants it.<P>Now, I have to find a generator for a good price...<P>------------------<BR>Don

Well, last night, one went on eBay. I was watching it and got busy teaching and forgot it. It went for a reasonable price. Oh well, more will come along...<P>------------------<BR>Don

eBay item 9705454270 is another Heath generator you might be interested in.<P>I have a couple of Sencore MX129 generators. Nice compact units but I haven't really done anything with them so I can't honestly recommend them.<P>There is a later Sencore, SG-165 I think, that comes up regularly on eBay and sells for around $100. It appears to combine a stereo generator, audio generator, and an output wattmeter.<P>-Steve W.<P>------------------<BR>

Hi Steve,<P>I should have an MX129 sitting on my back porch right now. I am out of town, teaching, coming home on the weekends. I won one of these on eBay a few weeks ago for a little of nothing. Hope it works. But Murphy's Law being what it is, I have the manual for the Heathkit and the item by Sencore. Go figure...<P>------------------<BR>Don

Old thread, I know.

Just wondering if anyone ever found, or scanned, the assembly and initial checkout section of the manual. I have the operating manual, schematic, theory of operation, and applications... pretty much everything but the actual assembly manual which usually includes preliminary checks.

I just found one of these in my pile of stuff and decided to restore it. I can get through it with what I"ve got but it would be nice to check the wiring first. For some reason I don't trust old kit builders. ...... oh wait, that's me .......

I have one and it can get the job done, but I've never been able to follow the factory adjustment procedure. There are two coupled coils that should function in a symmetric fashion, but I always have to offset them in an unexpected way. I've spent days trying to understand what the problem is, design or something wrong with my particular unit. Not a clue. The THD is fairly high on these, so they aren't suited to any really decent tuner. OTOH, they're way better than not having a stereo generator at all. Not sure if I have the assembly manual or not. I'd never pay more than about $50 for the unit, better to save pennies for an SG-165 or the small Leader LSG-231.

I had a Heathkit IG-5237 some years back and never did get it to work right. I purchased a Leader LSG-231 for around $100 and it works great.

Many years ago I built one and it did a good job. Unfortunately, it's gone forever.

I do have one of those Chinese modules that takes an audio input, and sends RF to the car radio. It's not high class but it does generate a useful stereo signal. And very cheap.

I think it was intended to take a CD player and create a signal in the FM band that the radio could receive.

Bill, I may just do exactly that lol. While I do like a challenge, I have many others that look like more fun than reviving this one. I got all the way through step one of the calibration before I hit a brick wall. This after replacing the power supply filter caps, which took more time than it was worth also. Oh well..... back on the shelf it goes until some blizzard this winter reminds me that I"ve got some useless projects waiting for me .......

I think I may start by testing all the tubes, eh ?? lol

EDIT: I decided to give it one more chance. Found the audio oscillator dead due to a burned out tungsten bulb, 110V 3W .... so on the shelf it goes until I find an actual BULB somewhere. Hopefully I've got one in a stash somewhere otherwise this might be a DOA unit. Not sure I want to bother ordering a bulb for it. The bulb is used in an oscillator as per a very old design, works well, very stable. Until all you can find are LED "bulbs" lol. If only the Heath engineers had predicted the demise of light bulbs...... I probably could figure out some substitute lamp but ... well, it's probably just not worth it ...

Found a bulb in my stash, installed it with great excitement, it made no difference. The generator is all buttoned up and on my shelf of "get to it maybe never" equipment. Almost one full day of work and no progress..... into the pile it goes.

Glutton for punishment that I am, I low-bid on a supposed working one from the auction site. If that fails I will consider it a lesson learned 4x over and look for a newer solid state generator. . Just something about Heathkit and my beginnings in electronics that's appealing ....

Barry, I checked and have this. I also checked and don't have it scanned. It is about 60 pages long. Is there a particular page/section or whatever that you need? I can scan that for you. I have one of these and I also have the later one with the BNC connectors. They are sitting in "Queue" as they say...

Possibly can scan the document later next week.

Thanks Don.. I took the manual and the generator back to the shop (or, more accurately, 'the pile') for a later day. I am missing a lot of pages... here is what I DO have though:

pg 1-5, 34-39, MPX alignment in 4 pieces (presumed to be page 40?) .. 41-55, and the schematic. These are all in quite good and legible condition except perhaps the MPX alignment but I can probably piece that together from what I've got already.

I am guessing 6-33 are the assembly and initial test instructions? But of course since I don't have it, I don't really know. .

If you prefer, you can mail it to me, I'll scan it and get it back to you. And post it on my website if anyone ever needs it again. I'll of course pay for postage both ways if you're up for this.

Thanks, let me know, and there is absolutely no hurry on this. I'm on the lookout for a solid state Leader or B&K in the meantime.....some adage about using your test equipment vs continuously repairing it ....

Barry

What is the bulb for?

The bulb is the "tungsten element" in a classic light bulb oscillator. I'd have to go to the wayback machine and look it up for the exact description but basically when the current through the bulb increases, this causes the light bulb to warm up (not enough to glow, though). When the temperature increases, the resistance in the light bulb increases, making the oscillator reach an equilibrium. Then it cools down in the reversse cycle, and repeats over and over.

You can read all about it, just google 'light bulb oscillator'. Very simple, very stable, and very cheap.

Tungsten bulbs are often used to stabilize a signal amplitude. In a Wien Bridge oscillator they limit the amplitude in a more linear fashion than having the tube or transistor start clipping to limit the amplitude. The clipping generates distortion.

Thanks Barry, still busy and I am not ignoring you!