need help identifying crystals

[52to12]

Hi! Hope someone can help me identify some crystals. I need to know if the following scanner crystals with markings of : KDS Japan p-77AH, Bomar A-5, Bomar C-7 and MRM-1 are for scanners with an 10.7IF or 10.8 IF .

 

[DaveH]

Try giving us the actual frequencies marked i.e the fundamental frequency
and the frequency it's designed to receive.

Dave

 

[52to12]

Hi Dave . Thanks for your quick reply! The only marikings on the crystals are:46.120,46.080, 46.220 all p77-al, 158.940 p77-ah all KDS Japan. 154.430 MRM-1-,162.550,Bomar A5 162.550, 160.025,160.220and Bomar c7. There are no other markings on the crystals that would indicat the "raw" frequency. Any suggestions/help is greatly appreciated.

 

[ChrisP]

I know that the ones marked "P-77" were for the Realistic PRO-77, which was a 10.7 IF scanner. I still have a ton of those crystals...

 

[DaveH]

If you have a crystal scanner available, even if the frequencies in question are
not in use in your area, you can at least determine which type of scanner they
are for, using the local oscillator. Plug in a crystal (VHF high-band), then look
for a signal 10.7 or 10.8 below the marked frequency. For 154.430, listen on
or around 143.73 (-10.7) and 143.63 (-10.8) with a second scanner.

I'm not too sure about the lowband crystals. They are probably fundamental,
high-side injection. For 46.12, you'd check 56.82 (+10.7) and 56.92 (+10.8)
if you have a receiver to cover that range.

Dave

 

[K5MAR]

Ken's Electronics has some information on identifying scanner crystals. Take a look here. There was another, more comprehensive list but I can't find it right now.

Mark S.

 

[KMA367]

Plug in a crystal (VHF high-band), then look
for a signal 10.7 or 10.8 below the marked frequency. For 154.430, listen on
or around 143.73 (-10.7) and 143.63 (-10.8) with a second scanner.

Every once in a while I'd be able to get double or even triple-duty out of scanner crystals. If I had a (Regency) 10.7 xtal for 460.125, putting it in a Bearcat (10.8) scanner would get me 460.225. Occasionally you could even get VHF-Hi and/or VHF low if the formula was right. I put together a quick matrix for it... manually, 25 years ago. Living in the big city it could be handy and save me a few $5 now and then. Cheapskate that I am.

 

[52to12]

Dave, thanks for your reply/help. I have to CONFESS!. I am totally scanner/electronic illetirate. Just bearly mastered on off and squelch. Does the second scanner have to be a craytal scanner?