I am considering purchasing an FM/AM Frequency Generator to align my tuners (mostly solid state from the 70's). I like to tinker and a tuner alignment is about the only thing I am yet unable to do with precision when restoring my receivers. It seems this is a specialized area. Can someone recommend a brand and model of Frequency Generator I should be looking for, preferably used for around US$500 and suitable for stereo FM.
I already own a frequency counter, oscilloscope, distortion meter and a 20Hz - 20kHz tone generator. Is there any other piece of equipment I will need to align a FM/AM tuner? Will I need a sweep generator?
Many thanks in advance.
I already own a frequency counter, oscilloscope, distortion meter and a 20Hz - 20kHz tone generator. Is there any other piece of equipment I will need to align a FM/AM tuner? Will I need a sweep generator?
Many thanks in advance.
I use an HP8640B. They typically have some internal problems with the gears (cracks) and switches but if you find a good one, or are handy with restorations, it's a super unit with better performance than just about anything out there. The specs say 500kHz to 500MHz, but they actually (and intentionally) go down to 455kHz for IF alignment. AM and FM modulation is whatever you send into the modulation jacks, so if you can't do what you need, you're probably better off with a service type unit specifically designed for stereo tuner alignment.
Best,
Conrad
Best,
Conrad
Ok
Here is one on ebray that looks like a good deal,
It will also do multiplex FM. It's fully synthesised and has calibrated output level.
NATIONAL PANASONIC VP 8177A FM/AM SIGNAL GENERATOR - eBay (item 370291633206 end time Feb-13-10 19:47:16 PST)
The manual is avaiable
http://www.freeinfostuff.com/Manuals/national_vp-8177a_owners.pdf
Just one idea
Here is one on ebray that looks like a good deal,
It will also do multiplex FM. It's fully synthesised and has calibrated output level.
NATIONAL PANASONIC VP 8177A FM/AM SIGNAL GENERATOR - eBay (item 370291633206 end time Feb-13-10 19:47:16 PST)
The manual is avaiable
http://www.freeinfostuff.com/Manuals/national_vp-8177a_owners.pdf
Just one idea
I've had my eye on this unit firechief but it does not seem to handle a stereo signal, Being a newbie, I was not certain how important the feature would be.
Jackinni
In the specificions section of the manual for the Panasonic unit that is for sale on ebay states:
"Separation for MPX stereo signal: >55 dB (test tone 1 kHz, 75 kHz deviation, RF 76-108Mhz):
Is this enough information for Black Gate to be sure that he can test his classic FM receivers? This is a synthesized rig for sale for only 288 dollars, and while not one of the more well known models, If it will fit the bill, the price is right. Oh, I just took another look at the sale. Why the heck are they asking 175 dollars for shipping. Whats up with that?
In the specificions section of the manual for the Panasonic unit that is for sale on ebay states:
"Separation for MPX stereo signal: >55 dB (test tone 1 kHz, 75 kHz deviation, RF 76-108Mhz):
Is this enough information for Black Gate to be sure that he can test his classic FM receivers? This is a synthesized rig for sale for only 288 dollars, and while not one of the more well known models, If it will fit the bill, the price is right. Oh, I just took another look at the sale. Why the heck are they asking 175 dollars for shipping. Whats up with that?
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The pilot tone for MPX is at 15KHz, so that's why there's a brickwall filter slightly below that, to prevent chirping
Well, I've looked at a Service Manual for a Sansui 9090DB. The first pic shows how the equipment is set up. The other pics shows what settings are needed on the equipment to align the tuner. In this instance, it seems that both a FM Stereo Signal Generator and regular FM/AM Signal Generator is required.
The Leader 3215 (mono) and 3216 (stereo) are nice instruments--I have a 3215 I got with a blown output transistor for $100 eBay. The output driver is a 2N3866A which is pretty rare these days, however I replaced it with an NTE311 and all is well...
Fully functional these command a premium price, $300-$400 for the 3215, $400+ for the 3216, however I have repaired and sold 2 or 3 dead 3215s that I've got for around $100 and not found any problem other than the output driver (it doesn't like being shorted), and power supply issues--I.e. easy stuff...
If you find one I have the service manual and schematics...
Fully functional these command a premium price, $300-$400 for the 3215, $400+ for the 3216, however I have repaired and sold 2 or 3 dead 3215s that I've got for around $100 and not found any problem other than the output driver (it doesn't like being shorted), and power supply issues--I.e. easy stuff...
If you find one I have the service manual and schematics...
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Leader 3216 Service Manual
Hi, I am searching for a service manual (not user manual) for the Leader 3216 signal generator now since 2 years, but without success. Reading your posts I think that you have one. Would you sell me a PDF copy of the service manual, so that I can finally start to repair my 3216? Any response would be very appreciated.
Hi, I am searching for a service manual (not user manual) for the Leader 3216 signal generator now since 2 years, but without success. Reading your posts I think that you have one. Would you sell me a PDF copy of the service manual, so that I can finally start to repair my 3216? Any response would be very appreciated.
The one stop solution would be a Sound Technology ST1000A generator. It has an RF section good enough to test the distortion limits on pretty much any FM tuner, some features that make IF alignment easy and a very good MPX generator. Some have a connection to allow an external counter to make sure you are on frequency. The attenuator has the dynamic range necessary to test the tuners sensitivity etc.
Its a little pricey at what seems to be a typical price of $500.
Here is some background and useful info on alignment in the links: Stan Curtis, Engineer, Sound Technology instruments, download service manuals and more here: Updating the Sound Technology 1000A
Its a little pricey at what seems to be a typical price of $500.
Here is some background and useful info on alignment in the links: Stan Curtis, Engineer, Sound Technology instruments, download service manuals and more here: Updating the Sound Technology 1000A
Hi guys,
I own a HP 8656B rf sg, I measure thd at around ~0.1-0.3%, depending on freq, using the HP 8901A and a Amber 3501. Even if I use the Amber 3501 audio osc, it makes no difference. I believe the majority of thd is in the 8656B.
I bought a HP 11715-60001 rf assembly (from a HP 11715A test set) to play with. I want to use it for my HP 8901A mod analyzer cal and checkout and to use as a precision RF generator for the fm commercial band receiver testing.
Funny how I was scouring Stan's great web pages and reviewing the 1000A manual lately. Damn I would like to find the Sm/schematics for the 1020A too. Any ideas guys? I have some ?'s about how the varactor linearizer works?
So short story is, I need a stereo modulator!! for my setup.
It can be as simple as
SIMPLE FM STEREO MULTIPLEX ENOCDER CIRCUIT
I think I want a bit better than above, so
In my search I see how Sound Technology has done it in the 1000A. uA709 opa's circa '75. I have started to do ltspice sim on some of the circuits. I was even thinking, it would be within my capabilities to re-design this product, even for my own use. Is it worth it?
I have not used my old TI transistor & Diode Manual so much.
So anyone have any ideas to my stereo modulator and general FM broadcast RF SG questions or should I start a new thread?
It is funny how Sound Technology got started as a niche market for specific fm rf sg and now people are still looking for them!!
I own a HP 8656B rf sg, I measure thd at around ~0.1-0.3%, depending on freq, using the HP 8901A and a Amber 3501. Even if I use the Amber 3501 audio osc, it makes no difference. I believe the majority of thd is in the 8656B.
I bought a HP 11715-60001 rf assembly (from a HP 11715A test set) to play with. I want to use it for my HP 8901A mod analyzer cal and checkout and to use as a precision RF generator for the fm commercial band receiver testing.
Funny how I was scouring Stan's great web pages and reviewing the 1000A manual lately. Damn I would like to find the Sm/schematics for the 1020A too. Any ideas guys? I have some ?'s about how the varactor linearizer works?
So short story is, I need a stereo modulator!! for my setup.
It can be as simple as
SIMPLE FM STEREO MULTIPLEX ENOCDER CIRCUIT
I think I want a bit better than above, so
In my search I see how Sound Technology has done it in the 1000A. uA709 opa's circa '75. I have started to do ltspice sim on some of the circuits. I was even thinking, it would be within my capabilities to re-design this product, even for my own use. Is it worth it?
I have not used my old TI transistor & Diode Manual so much.
So anyone have any ideas to my stereo modulator and general FM broadcast RF SG questions or should I start a new thread?
It is funny how Sound Technology got started as a niche market for specific fm rf sg and now people are still looking for them!!
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The fundamental trick is to balance one curve against another to find the most linear balance if the two and use only a small segment of the curve. it works well on the ST1000a. The manual describes the trick and how to tune it. I managed it on mine pretty well and really got tot he distortion floor of the Boonton modulation analyzer and the Onkyo and Yamaha tuners I used with it.
Having a good spectrum analyzer and the ability to look at Bessel nulls helps.
Some of the most recent FM transmitter chips would be as good or better using some really exotic modulation schemes etc. That business got really nuts and then cars got aux jacks and it died.
Having a good spectrum analyzer and the ability to look at Bessel nulls helps.
Some of the most recent FM transmitter chips would be as good or better using some really exotic modulation schemes etc. That business got really nuts and then cars got aux jacks and it died.
Thx Demian for your explanation. I received the 11715A-60001 assembly yesterday. It is a later model(~1999), National 10C11 ecl pre-scaler/divide by 4 is replaced by a SP8610B and some other changes.
I think with the 11715A, thd spec of <0.025%, it is good enough for my requirements. I will measure it, I think I have the necessary test equipment for the fm distortion test #4-8.
I do not own a spectrum analyzer either, one day maybe and I can re-visit Bezzel.
When I finish the basement reno, hopefully before xmas, I will at least test it out and report my findings.
I am using the Silicon Lab receiver parts, if those are the ones you are referring too, something else to try, Si4710/12.
I also noticed MRDS1322 from Pira.cz for the rdbs/rds function of my generator.
I think with the 11715A, thd spec of <0.025%, it is good enough for my requirements. I will measure it, I think I have the necessary test equipment for the fm distortion test #4-8.
I do not own a spectrum analyzer either, one day maybe and I can re-visit Bezzel.
When I finish the basement reno, hopefully before xmas, I will at least test it out and report my findings.
I am using the Silicon Lab receiver parts, if those are the ones you are referring too, something else to try, Si4710/12.
I also noticed MRDS1322 from Pira.cz for the rdbs/rds function of my generator.
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