Best AM FM Stereo RF Generator for a Newbie

[Peter S]

Hi Folks; As usual, getting into projects way over my head. Hoping this old dog can still learn a few tricks. Can anyone suggest a reasonably priced RF generator for FM stereo tuner alignment? Been watching some youtube videos on the procedure---real edge-of-your seat stuff! I saw some pretty exotic HP gear but the unit required an external stereo (multiplex?) modulation source. Ideally looking for an all-in-one gadget.
Thanks and Happy New Year!

 

[George S.]

I have a Panasonic VP-8193A. Very easy to use and most probably one of the most accurate stereo FM signal generator models on the planet. HP never made a stereo unit.
They come up occasionally on eBay. Don't be shy about submitting a low offer on used test equipment. Quit often they have pallets of product they just need gone.
Hint: Do a eBay search for "Panasonic VP". Over time I've seen lots of high quality interesting test equipment.

 

[George S.]

My unit came out of the Boston area. I watched for about 9 months until the low priced unit showed up, saw he had a very large amount of similar test equipment, and sent a $200 offer. He accepted, another $60 for shipping.
Throughout the 90's we used to haul truckloads of computers and electronics to Andover MA for warranty repair and reconditioning for resale. Those receiving facilities were full of processing lines and test equipment. I think the unit came out of such a facility when it closed.
Peter, if your patient and you watch, you'll find a similar deal.
And, nothing wrong with a Heathkit, Sencore, or Sound Technology. Rumor is Sound Technology was established by HP engineers. They produced what HP wouldn't.

 

[Peter S]

Hi George;
Thanks for the info. I'm at the very beginning of the learning curve but figured I should keep my eyes open now since this is specialized gear.
I have heard the Panasonic name come up a few times. I think you got a heck of a deal! The Sound Technology 1000A is mentioned in a Marantz service manual. I was concerned that the Sound Technology model was getting a little 'long in the tooth'... but I guess so is the equipment it was designed to service.

 

[George S.]

Hi George;
Thanks for the info. I'm at the very beginning of the learning curve but figured I should keep my eyes open now since this is specialized gear.
I have heard the Panasonic name come up a few times. I think you got a heck of a deal! The Sound Technology 1000A is mentioned in a Marantz service manual. I was concerned that the Sound Technology model was getting a little 'long in the tooth'... but I guess so is the equipment it was designed to service.

Yup, most of the older FM Stereo test equipment has been tinkered with and rebuilt right or wrong at this point. Lots of documentation is out there about fixing and aligning it for use.

 

[Peter S]

I see a NATIONAL PANASONIC AM-FM SIGNAL GENERATOR VP-8178B for sale on epay. It's close by in Toronto but from the owner's manual, it seems that an external modulator would be required for FM Stereo ( unless I'm still all wet about this)----and they're asking almost $900 CDN!!
Looks like a fairly new machine but why no FM Stereo?

 

[George S.]

National and Levear are two other names you'll find these under. Not all came with the stereo functions.
I have a Boonton AM/FM rf signal generator made for general radio repair that doesn't support FM Stereo alignment.

 

[George S.]

Peter, FM Stereo is a small portion of the radio market. Most civilian, government, and military radio was strictly AM or FM when these were made. That's one reason why good FM Stereo alignment test equipment is expensive. A very specialized market. No one was buying these to tuneup a CB or shortwave receiver.

 

[Peter S]

Hi George, you mentioned Heathkit. Would these units have been built from a kit? (sorry if for dumb question) or did Heathkit ever sell assembled equipment?
I have an addiction to Leader test gear but their full-fledged generator is way out of my budget. Leader had a small FM stereo generator ( LSG-231) but it only has one RF carrier frequency; 100 MHz. I would love to get my hands on one but it seems like this would not be adequate for a complete alignment (obviously)

 

[George S.]

I think Heathkit came both ways. I've seen one in a photograph of Glenn's bench. Hopefully he'll comment on what he thinks of it. I did research the Heathkit and remember a good video about the FM Stereo alignment unit.
As for the Leader, maybe it'll work for you. They seem to have made good equipment.
I can only suggest reading and looking for a video of that Leader.

 

[nakdoc]

The Sound Tech 1000A was the standard for audio manufaturers. Current used pricing is $500. It really shines if you are working on older tuneable IF stages (ala Marantz 10B and vinyage tube McIntosh). The 1000A had an option (003 IIRC) which lowered THD to 0.05%. Option 001 was a switchable internal 400/1000 Hz oscillator. I would have no concerns about the age of a 1000A. Note that it should have an external 50 to 300 ohm matching transformer if you plan to make accurate sensitivity measurements.
The Sencore SG165 is a cheap and dirty AM+FM signal generator with stereo and built in loads. THD was about 0.25%

 

[Peter S]

The Sound Tech 1000A was the standard for audio manufaturers. Current used pricing is $500. It really shines if you are working on older tuneable IF stages (ala Marantz 10B and vinyage tube McIntosh). The 1000A had an option (003 IIRC) which lowered THD to 0.05%. Option 001 was a switchable internal 400/1000 Hz oscillator. I would have no concerns about the age of a 1000A. Note that it should have an external 50 to 300 ohm matching transformer if you plan to make accurate sensitivity measurements.
The Sencore SG165 is a cheap and dirty AM+FM signal generator with stereo and built in loads. THD was about 0.25%

Thanks Doc! I will keep that in mind regarding the 1000A vs SG165. I have seen many references to both units but was not aware of the quality differences. I would prefer to obtain either of these units rather than a more expensive HP unit that would still require an external FM stereo modulator.

 

[George S.]

Peter, a 50 to 75 ohm matching pad I use to connect the Panasonic's 50 ohm output to 75 ohm cable and then the tuner.
Various FM Stereo alignment generators use different output impedances. Having the correct matching pad is helpful, but not critical.

 

[Peter S]

Thanks George. If I can find a deal on the generator, I won't mind shelling out for a matching transformer. I'll also need some plastic allen keys and other various non ferrous tweakers.

 

[George S.]

There are other "work around" options.
https://groups.io/g/FMtuners/message/93235
I'm going to order one to use in my 94 Chevy dustbuster minivan with the original Delco radio cassette player as my Google phone only has a usb C port. Then I can stream music, podcasts or Radio Garden.
This could also be used for FM tuner alignment. Another thread is here.
https://groups.io/g/FMtuners/topic/96611391

 

[Peter S]

Thanks George. I have heard of such devices used for alignment. Let me know how it works for your minivan. Without a cellphone, could audio be introduced from a laptop with bluetooth? Still wouldn't look as cool as this on the bench!

 

[BlueCrab]

I have both a Sencore SG165 and a Leader LSG-231 (the Leader 3214 in the previous reply is newer). Both are ok for older analog tuners, but both need to be gone over with a fine tooth comb to ensure they are working to spec. I wouldn't use them to align newer tuners except to check for gross mis-alignment.

 

[George S.]

Peter, did you get the Leader?

 

[Peter S]

Hi Jim, thanks for the info regarding the older test gear. I would definitely not mind going over a nice piece of gear like that with a fine tooth comb. I learned my lesson over my last PL700 II that was completely WOPL'ed. I left one old cap remain, the filter cap on the LED meter board and now I have to wrestle the amp out of the rack again, just because the power meters sit two notches above zero.
No George, I haven't found that unit yet, just drooling over audio porn!

 

[George S.]

Thanks George. I have heard of such devices used for alignment. Let me know how it works for your minivan. Without a cellphone, could audio be introduced from a laptop with bluetooth? Still wouldn't look as cool as this on the bench!

Using it in the truck today. Works excellent. Been listening to various Australian FM stations on the Radio Garden app.
This would make a decent tool for FM alignments if nothing else was available. Frequency still needs to be checked to make sure it's accurate, but appears to be. It's worth getting. I like it. Bought two, one for the truck and another for the old Chevy van.