Redco FM 30

[Redbeard U812]

Anyone have a manual for this:

Borrowed these pics off Ebay. Mine works, just a little off. Wondering if there is information to calibrate. CB Tricks does not have anything I could find. They have the hardwired variety to the PLL.

 

[loosecannon]

can you take some pics of the inside of your counter?

most likely there is just one little trimmer in there (possibly two) that needs to be adjusted to put it on freq.

10 mhz is a pretty standard freq to inject for calibration.
just make sure that the thing you use to provide the 10mhz signal is ACTUALLY accurate for 10.000000 mhz. otherwise you just end up with two devices that are off freq.
LC

 

[Redbeard U812]

LC, so definitely true. it's only off .0013 above actual.
Seems there is only one. The crystal next to it is stamped 10.000

 

[loosecannon]

RedbeardU812,

yep, looks like its just the one trimmer in the lower left corner.

if you want to restore the counter so that it will work for a long time, replace those two big grey electrolytic capacitors with new ones.
then re-grease that one transistor tab that is mounted to the bottom cover. be sure to use the white non-conductive grease, and not the grey/silver conductive stuff that many use for their computers. (this transistor may or may not be isolated from the chassis, and therefore may or may not have any compound on it. to me it looks like i see an insulator there, which would mean it should have some compound on either side of that insulator)

also, just out of morbid curiosity, what instrument are you using to determine what 'actual' is?
LC

 

[loosecannon]

BTW, here is a manual for it, not that it really tells you anything LOL.

http://messui.polygonal-moogle.com/cb/fm30.pdf
LC

 

[Redbeard U812]

RedbeardU812,

yep, looks like its just the one trimmer in the lower left corner.

if you want to restore the counter so that it will work for a long time, replace those two big grey electrolytic capacitors with new ones.
then re-grease that one transistor tab that is mounted to the bottom cover. be sure to use the white non-conductive grease, and not the grey/silver conductive stuff that many use for their computers. (this transistor may or may not be isolated from the chassis, and therefore may or may not have any compound on it. to me it looks like i see an insulator there, which would mean it should have some compound on either side of that insulator)

also, just out of morbid curiosity, what instrument are you using to determine what 'actual' is?
LC

Out of morbid sense of humor I am basing my assessment only on two radios which I know are on freq......

.......and to add, I merely plan to moderately whistle into a microphone to simulate a 10KHz tone.

 

[Redbeard U812]

I hereby retract the formal use of the word "actual" and wish to inject the words "It looks to be". Therefore appeasing the PC out there. [tongue in cheek] Should the House Sub- committee open a fishing expedition.

Thanks for the manual LC

 

[loosecannon]

LMAO that was funny!

if one of those radios is a relatively new ham radio with a known history then i would say go for it, but if they are CB radios, i would have to know that they were just tuned by a shop that had accurate test equipment.

you can build your own 10mhz frequency standard, but of course you have to have that set up too.

good luck with the counter.
LC

 

[Redbeard U812]

 

[Redbeard U812]

Ha, ha.....guess it needs a new trimmer added to the PM list too. Has been off for some time, guess I know why now.

 

[nomadradio]

I'd say it's a tossup between the 10 MHz crystal, the trimmer cap, or both.

A crystal is a moving part on the inside. Mileage counts, so if it was used a lot of hours, the crystal may have drifted too far for the trimmer cap to correct. Age alone can do this, as well.

The pivot inside the trimmer can behave like a scratchy volume control. If oxidation makes it change the crystal frequency in an erratic way, it should probably go. Eavesdropping on the crystal is the best way to tell this. If you have a SSB receiver that can hear 10 MHz, connect a coax jumper to it, with the center pin of the other end alongside this crystal. Tune it in and see if the frequency moves smoothly up and down as the trimmer cap is turned. You'll know right away if the trimmer cap has become noisy.

73

 

[Redbeard U812]

Oooo....neat.

 

[Redbeard U812]

Friend has an old military receiver that could do that. Figure I can entice him with alcohol and a tech quiz. Just have to take it over there.