[George Kirk]

Hello Ron
When the ice melts enough so I can get into my shop will see if I have that manual, I did warranty work for Fisher back in the day.

[Ron Ramirez]

George, that would be great, thank you! Although my 4400 is working very well now, the factory manual would be a big help if I need to service it in the future. It will also come in very handy if/when I give this unit a complete alignment - once I get my hands on a good AM/FM stereo generator/analyzer, that is.

You wouldn't happen to have any leftover Fisher parts/parts sets, would you?

[Mondial]

Ron, if you want a really good FM stereo generator, try to find one of these. It was the best available for many years and now they are available at reasonable prices.

http://www.ebay.com/itm/VINTAGE-SOUND-TE...7675.l2557

I have had one for over 30 years and love it. None of the service grade generators or analyzers even comes close.

[Ron Ramirez]

I found another one:

http://cgi.ebay.com/181265593402

For $1K, it had better automatically repair and align all of my FM receivers without human intervention, order, pay for and install all needed electrolytics and other parts, do my laundry, and send a Pam Anderson clone to Tom Forbes.

I've been watching for one of these:

http://cgi.ebay.com/141197542033

This one appeals to me because you can connect the receiver outputs to built-in dummy loads within the unit and then use the meters for alignment without having to listen to the tone from the generator.

[Mondial]

Well, I certainly would not pay anywhere near $1k for a Sound Tech, but for $250 or less they are a great deal. They are always in demand and you could use it for 5 years and then sell for more than you paid.

The nice thing about the ST is that it generates a modulated RF MPX signal, so you can just connect the generator to the ant terminals and be done with it. Its basically a high quality calibrated FM stereo transmitter. It also has a dual sweep function which makes it easy to align the IF for maximum linearity.

From what I understand the SG165 does not modulate the MPX signal on the FM RF carrier, so you have to insert the MPX signal directly into the receivers decoder circuitry. Its FM RF output is very low level and useful only for peaking the front end.

This link gives some of the specs for the ST 1000A:

http://wd4eui.com/Sound_Tech_1000A.html

[Ron Ramirez]

Its FM RF output is very low level

You mean as in "too low for a frequency counter to pick up"?

If that is the case...

D'oh! Did I return a working Sencore SG-165? I bought one that was advertised as in "full working order," could not get any FM signal to read on my B+K frequency counter, so I returned the darn thing.

If that is true...I think I am going to be sick.

But on the bright side...if a Sound Tech can be acquired at a reasonable price, perhaps it was all for the best.

But wait. Does the Sound Tech provide a 10.7 MHz signal for FM IF alignment?

[BrendaAnnD]

I have one similar to this one. Very nice units indeed. If you were to buy this particular one, I might be able to save a significant amount on shipping by having the seller ship it here, and me forwarding it.

http://www.ebay.com/itm/Jung-Jin-FM-Ster...1279599338

[Mondial]

Yes, most likely the SG165's FM RF output is too low for a counter to read directly. Unfortunately, there may have been nothing wrong with the unit you sent back. Without an RF millivoltmeter, the only way to check would have been to connect it to a FM receiver and listen for the RF carrier.

If there is one downside to the ST 1000A its the lack of a 10.7 MHz output for aligning the IF. Personally I have never seen this as a problem as I typically use a standard signal generator to peak the IF at 10.7 and provide a marker. Then use the sweep output of the ST to optimize the response and adjust the FM detector for max linearity. The ST provides its sweep output as RF from 88 to 108 MHz, so it sweeps the entire receiver from front end to detector.

The ST's dual sweep function modulates the swept signal with an additional 10 kHz frequency. You feed the RF sweep into the ant input then pass the receiver's output through a filter in the ST, which removes the low freq sweep but passes the 10 kHz signal. When you look at the 10kHz on a scope, you should see a flat amplitude across the swept bandwidth. If there is any tilt or variation to the amplitude waveform then the IF or detector is nonlinear and needs tweaking.

The nice thing about the setup is that you can check the IF and detector alignment without even taking the cover off the receiver. Just feed in the sweep signal at the ant terminals and look at the demodulated output on the scope.

[Ron Ramirez]

Brenda - I appreciate the offer, but $370 plus shipping from Korea is a little more than I wanted to pay for a signal gen.

I asked the seller to return the Sencore to me, and I paid for the shipping of course, plus a little extra for his trouble. I consider it a "dummy tax" for my error. I don't mind - since I bought that unit, other SG-165s advertised as "not working" have sold for more $$$ than mine. It will be re-delivered to me this evening.

[BrendaAnnD]

Ron,

Well, it wouldn't have been shipping "from Korea", it would have been shipping from the left coast.

Yeah.. most signal generators don't really put out enough signal to drive a freq counter. And the older ones that DO have enough are usually not clean enough (sometimes on purpose) to get a decent reading on.

[Ron Ramirez]

Yes, I know...sorry I didn't clarify that. Still, I had set an upper limit of $200 which may, or may not, have been a reasonable limit.

I guess I was just spoiled by my old Clough-Brengle AM-SW signal gen, which does put out enough signal to drive a freq counter. I modified my C-B to add a second output at full power (bypassing the output adjustment controls), terminating in a BNC connector. A cable runs from this to my B+K freq counter, so I always know what frequency the C-B is dialed to when performing alignments on the old Philcos. The BNC connector is in place of the old "external modulation input" jack, so the mod is fully reversible.