Is there any difference between an RF signal generator and FM signal generator?

[ChopperChas]

I found a good price on an "RF Signal generator". Is this the same thing as an FM signal generator? I'm guessing not, but I figured I'd ask.

Charles.

 

[ConradH]

An FM sig gen is an RF sig gen, but an RF sig gen may or may not be an FM sig gen. Since FM sig gens are a very small portion, if you're shooting darts it's unlikely you'll hit one. Do you have a brand and model number?

 

[ChopperChas]

Okay, I understand the difference now. Alas, it's not an FM signal generator. Looking for one in the ~$50 range so i can align my tuner.

Charles.

 

[Pio1980]

You need an FM signal generator to align an FM tuner, and it should have the multiplex portion to align the stereo demodulator. You really need an oscilloscope to get it right.

 

[RossW]

Finding a $50 generator that will be useful for tuner alignment will take a great deal of luck. One that can do stereo modulation can easily set you back $300+. I've been getting into tuner alignment lately and believe me, it is not cheap or easy.

 

[ChopperChas]

None of the service manuals for the tuners I have indicate the need to use an oscilloscope. Although, they're all digital tuners. Dunno if that makes a difference.

Charles.

 

[BinaryMike]

Many RF signal generators come with built-in AM/FM modulation capability, but you would have to add an external stereo multiplex encoder to fully align FM broadcast tuners. It's not unreasonable to make your own stereo encoder, but then there's the issue of modulation distortion -- a low cost RF generator might not have low enough distortion to properly test and calibrate high-performance FM tuners.

 

[ConradH]

Every tuner alignment procedure I've seen assumes you already have a pretty good understanding of how to do it, plus enough experience to ignore the ever present errors and add procedures they didn't bother to talk about. The best/cheapest starting point is probably to get an SG-165 and some junkyard receivers and have at it. Yes, you need a scope, and a frequency counter is highly desirable. There are some matching networks you'll probably have to build. Unless you make it a full time study project, figure 6 months to a year of fiddling around before you feel confident. FWIW, from the time I decided I wanted to do it, to the time I was equipped and maybe halfway competent, was probably more than two years. BTW, most of the FM generators you'll find for a reasonable price are quite old and will need a rebuild and calibration before they work! I don't want to be discouraging, in fact I recommend learning this, but there's a reason so few people do it.

Start here- http://audiokarma.org/forums/index.php?threads/what-equipment-do-i-need-to-align-fm-tuners.594158/

 

[ChrisMarantz]

I've been getting into tuner alignment lately and believe me, it is not cheap or easy.

It becomes much easier after the 50th tuner. . . - Chris

 

[pustelniakr]

Before you begin buying test equipment, you need to tweak the most important piece, and that is between your ears. Here is what you need to do that: http://www.ebay.com/itm/troubleshoo...613184?hash=item3d2492eac0:g:aS8AAOSwgmJXyeKm

The book is in pretty high demand, so prices are rising on existing copies, since the book is out of print. Basic electronic knowledge is a prerequisite for understanding this book, so, if you don't have that, you will need to absorb a volume like this one: http://www.ebay.com/itm/The-Art-of-...893053?hash=item2cb28923bd:g:YmYAAOSwFe5Xy5aG

Absorb that stuff and you will be ready to begin thinking about diddling tuners. Without the requisite knowledge, tuners become paperweights most of the time.

Enjoy,
Rich P

 

[ChopperChas]

Okay, you've all done your job to completely discourage me. I'll just keep buying and reselling tuners until I get one that has good reception. They're cheap enough. I've got a couple good ones already. The Pioneer TX-940 are easy to adjust - per the manual, all you need is a voltmeter, and there are only two important adjustments. If I want a different kind of tuner for a different system, I'll just buy a few until I get one with good reception, and then resell the rest.

Charles.

 

[arts]

Don't give up just yet Charles. If this is something that you are interested in,pursue it! If you already have electronics skills,acquiring the knowledge and test equipment to do this type of work is really not all that difficult.But,as Rich said,you really do need to get you theory down pat before you start mucking about.

Here's a link to another interesting read on the subject.Chapter 9 gives you a rundown of basic alignment procedures.

http://www.smcelectronics.com/DOWNLOADS/1970-FMRADIOSERV.PDF

Art

 

[ChopperChas]

Honestly, I'd rather concentrate on the big Pioneer cassette decks. I just want to get a couple of tuners that work well, and then not worry about them anymore. I don't use my tuners often, but when I do I want to be able to pull in the low-power college station out of Raleigh (88.1 WKNC). Cassette decks are more of a deep love of mine. Cassette and R2R are what I listen to most often, and I'd like to learn the ins and outs of calibrating the big Pioneer decks. So I'm acquiring test tapes and gear to learn that. I've got a bunch of decks to practice on as well.

Charles.

 

[Binkman]

Greetings; I"m in Raleigh NC and have a good Onkyo tx-82 with remote, not large at al and a good phono section and cd plus tv out. I also have a Mcs tuner and cassette (silver combo, model not sure of model numbers as in storage but made by NEC and pulls stations very well plus the cassette has been serviced and does all metal tapes, too. No phones on either the nec tuner or player as was part of an integrated.

Couple of pointers in tuning in NC central areas. Signals received are much better with a dipole mounted vertically at 75ohms vs. 120.