FM/AM Frequency Generator Recommendations - diyAudio
Go Back   Home > Forums > Design & Build > Equipment & Tools

Equipment & Tools From test equipment to hand tools

Please consider donating to help us continue to serve you.

Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving
Reply
 
Thread Tools Search this Thread
Old 4th February 2010, 10:43 AM   #1
diyAudio Member
 
Join Date: Aug 2009
Location: Adelaide
Default FM/AM Frequency Generator Recommendations

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.
  Reply With Quote
Old 4th February 2010, 01:59 PM   #2
diyAudio Member
 
Join Date: Mar 2007
Location: Canandaigua, NY USA
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
__________________
I may be barking up the wrong tree, but at least I'm barking!
  Reply With Quote
Old 4th February 2010, 11:21 PM   #3
diyAudio Member
 
firechief's Avatar
 
Join Date: Sep 2008
Location: Near Seattle Wa
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...77a_owners.pdf

Just one idea
  Reply With Quote
Old 4th February 2010, 11:32 PM   #4
diyAudio Member
 
Join Date: Aug 2009
Location: Adelaide
Thanks for that Conrad.
  Reply With Quote
Old 4th February 2010, 11:36 PM   #5
diyAudio Member
 
Join Date: Aug 2009
Location: Adelaide
Quote:
Originally Posted by firechief View Post
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...77a_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.
  Reply With Quote
Old 5th February 2010, 12:17 AM   #6
diyAudio Member
 
firechief's Avatar
 
Join Date: Sep 2008
Location: Near Seattle Wa
I understand, perhaps someone could look at the manual and give us some enlightment. The FM stereo signal uses somthing called (I think) a 9Khz subcarrier, and it really isn't clear to me if that is included. We may both learn something.
  Reply With Quote
Old 5th February 2010, 03:39 AM   #7
star882 is offline star882  United States
diyAudio Member
 
star882's Avatar
 
Join Date: Mar 2007
Nowadays, cheap FM transmitters often use crystal-referenced PLLs. Best bet to find one of those is to look for one with a digital frequency selector. If your frequency counter goes high enough, you can use it to verify accuracy.
__________________
"Fully on MOSFET = closed switch, Fully off MOSFET = open switch, Half on MOSFET = poor imitation of Tiffany Yep." - also applies to IGBTs!
  Reply With Quote
Old 5th February 2010, 03:58 AM   #8
diyAudio Member
 
jackinnj's Avatar
 
Join Date: Apr 2002
Location: Llanddewi Brefi, NJ
Sencore SG-165 -- prices range all over the lot. There was probably a Heath or Eico unit as well.
  Reply With Quote
Old 5th February 2010, 12:29 PM   #9
diyAudio Member
 
firechief's Avatar
 
Join Date: Sep 2008
Location: Near Seattle Wa
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?

Last edited by firechief; 5th February 2010 at 12:34 PM.
  Reply With Quote
Old 5th February 2010, 12:38 PM   #10
Glowbug is offline Glowbug  United States
diyAudio Member
 
Glowbug's Avatar
 
Join Date: Feb 2006
Location: Hillsborough, NC
Quote:
Originally Posted by firechief View Post
I understand, perhaps someone could look at the manual and give us some enlightment. The FM stereo signal uses somthing called (I think) a 9Khz subcarrier, and it really isn't clear to me if that is included. We may both learn something.
The pilot tone for MPX is at 15KHz, so that's why there's a brickwall filter slightly below that, to prevent chirping
__________________
Jim
The machine does not isolate us from the great problems of nature but plunges us more deeply into them. - Antoine de Saint-Exupéry
  Reply With Quote

Reply


Hide this!Advertise here!
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
FM Stereo Generator...uses? redrabbit Analogue Source 7 20th February 2009 07:55 PM
Frequency generator software REALFLEO Parts 5 7th December 2006 01:39 PM
low frequency generator computer software? player_low Parts 3 30th October 2004 06:16 AM
Frequency Generator Bryan Parts 10 17th March 2004 06:39 PM
How can I connect a frequency generator (BNC) to an amp (RCA) ? Bricolo Parts 3 20th November 2003 08:47 PM


New To Site? Need Help?

All times are GMT. The time now is 06:22 AM.


vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2014 DragonByte Technologies Ltd.
Copyright ©1999-2014 diyAudio

Content Relevant URLs by vBSEO 3.3.2