Sig gen for FM alignment, diy?

[Conrad Hoffman]

I want a signal generator for high quality FM tuner alignment. I know the Sound Technology units are supposed to be common, but I never see any come up for sale. I don't do much RF, but have an HP3200B, an old Heathkit IG-42, and a Tektronix 191. Can any of these be beaten and coerced into doing the job? Is there some other semi-affordable unit besides the S-T I should look for? Can anyone suggest a diy circuit specific to the purpose? I can build about anything, but I don't want it to become another multi-year project to finish! Thanks

 

[rdf]

Hi Conrad. The ST boxes show up on Ebay regularly, generally in the $300 range for a good one. I already have too many boxes and wonder if something like this:

http://www.aareff.com/1wpllkit.htm

in combination with PC analysis software wouldn't work for most basic setup needs. It's one of the few kits with specs, and they look pretty good.

 

[gootee]

HP8640B is a well-liked one.

I don't know what sort of features you are wanting or needing. But you might want to check http://www.govliquidation.com , using the Advanced Search features to specifiy the nearest warehouses that participate in the big monthly test equipment auctions, and also specify the sale number for one of those TE sales (especially after it's close-enough to the sale date for it to be fully lotted).

You could probably pick up several AUL SG-1144/U units for the minimum bid, and might luck out and get something like an HP 8640B, cheap-enough; probably in the $100 to $250 range, but with no guarantees. (I've actually got a half-dozen or so probably-not-quite-working-perfectly SG-1144/U AM/FM/CW sig gens left over, here. I just hate the thought of packing and shipping them, or even just looking at them.)

 

[Conrad Hoffman]

The pcb kit is really neat, but the HP unit looks like just what I need, and there's a bunch on eBay. No doubt after Christmas when I have the money, there won't be any to be had, but I'll put it on my watch list. Thanks!

 

[TerryC]

I purchased the article download for this kit a while back, but don't do enough FM work to justify building it. It looks pretty decent...


http://www.elektor.com/magazines/2006/june/fm-stereo-test-transmitter.58268.lynkx

 

[jackinnj]

I want a signal generator for high quality FM tuner alignment. I know the Sound Technology units are supposed to be common, but I never see any come up for sale. I don't do much RF, but have an HP3200B, an old Heathkit IG-42, and a Tektronix 191. Can any of these be beaten and coerced into doing the job? Is there some other semi-affordable unit besides the S-T I should look for? Can anyone suggest a diy circuit specific to the purpose? I can build about anything, but I don't want it to become another multi-year project to finish! Thanks

Wanna borrow my Sencore SG165? I picked one up on EBay a couple years back.

 

[Conrad Hoffman]

Very generous Jack, but I've a need to own! In fact, I've got a bid in on one of those right now. I'm still lusting after the HP unit, and if I get one of those, I can probably sell off my other RF generators. All the other generators are just LC oscillators, and I can't believe there isn't some simple way to add limited FM capabilities with a varactor diode or something.

 

[Conrad Hoffman]

Well, an HP 8640B should be on its way to me soon. No idea of the condition, but it went for less $$ than the Sencore SG165 did, and I am an HP snob.

 

[jackinnj]

Conrad, that is shocking. I thought the 8640's went for $600 or so.

I have a 3336B Synthesizer from HP and I use it all the time.

I bought my Sencore for less than $30.

 

[Conrad Hoffman]

IMO, the best time to buy test equipment is during the holidays, on friday night, or whenever you think people aren't paying attention. I think the SG165 went for around $160 or $180. An eBay search of completed will bring it up.

 

[jackinnj]

On my first job in finance I used to help out over the Christmas holidays as the trust departments in NYC would unload boatloads of stocks which they got in from estates -- little OTC companies that their analysts had no intention of covering -- my boss would sell them in February when things got back to normalcy -- that's why he had a house in Westhampton.

One firm that I worked for had their fiscal year ending November 30th so they could baloon their balance sheet at the end of the calendar year for exactly this same purpose.