Scanner Crystal Confusion

[colbrz1319]

GREETINGS MEMBERS, I am in the midst of restoring both a REGENCY 10.7 Scanner, as well as a ELECTRA BEARCAT 10.8 Scanner. I understand that crystals are interchangeable, but a stroke I suffered, precludes me from being confident in my efforts to figure out the formulas I have read up on. Could someone quickly explain where, and how, I calculate the 3rd Overtone, 10.7, and 3rd Overtone 10.8 formulas to use a REGENCY Crystal in a BEARCAT model, as well as using a BEARCAT Crystal in a REGENCY Model. I do have the crystals in hand, with the frequencies stamped on them, but I must be entering them incorrectly in the conversion formula. I need help with Low Band, VHF-HI, and UHF "formulas." Thanks.

 

[nd5y]

Scanner Crystals - The RadioReference Wiki

 

[DickH]

GREETINGS MEMBERS, I am in the midst of restoring both a REGENCY 10.7 Scanner, as well as a ELECTRA BEARCAT 10.8 Scanner. I understand that crystals are interchangeable, but a stroke I suffered, precludes me from being confident in my efforts to figure out the formulas I have read up on. Could someone quickly explain where, and how, I calculate the 3rd Overtone, 10.7, and 3rd Overtone 10.8 formulas to use a REGENCY Crystal in a BEARCAT model, as well as using a BEARCAT Crystal in a REGENCY Model. I do have the crystals in hand, with the frequencies stamped on them, but I must be entering them incorrectly in the conversion formula. I need help with Low Band, VHF-HI, and UHF "formulas." Thanks.

They are not interchangeable. Bearcat xtals will not work in a Regency and vice versa.

 

[w8prr]

Almost all scanners except the Bearcat use the 10.7 crystal, If you just need a couple of frequencies PM me, I may be able to help, have about 500 10.7 crystals on hand, plus a few 10.8

 

[W3DMV]

Chart To Help

chart

 

[colbrz1319]

THANK ALL OF YOU FOR THE ASSISTANCE. I based this question after viewing a "crossover" chart on KEN'S ELECTRONIC'S of Michigan website. On the Home Page, I invite everyone to Click on "CRYSTALS" and then there is a link to the formula's as well as a "crossover/swap" chart, at the bottom of that webpage. Where I became thrown off, was the "conversion" formula math results, took me to a frequency not part of the traditional FCC "spacing" whether ole school or narrowbanding frequencies.

 

[oracavon]

They are not interchangeable. Bearcat xtals will not work in a Regency and vice versa.

Actually, they will work if you allow for the IF difference and select the crystal frequency accordingly. I picked up the information below somewhere on the internet in the past, but I can't remember where. However, using this information, I have successfully used Bearcat crystals in my Regency scanners. For example, a 42.58 Mhz Regency crystal (10.7 IF) will receive 42.48 Mhz in a Bearcat scanner (10.8 IF), and vice-versa.

Here is the info:

Interchangability of Scanner Crystals "Regency" & "Bearcat" crystals are not the same; however you can use BC (10.8MHz IF) crystals in place of TMR (10.7MHz IF) crystals (& vice-versa) when you consider the IF frequency to determine the frequency it would receive in a different brand scanner:

Regency 42.580 TMR receive = (3rd overtone 53.2800) = Bearcat 42.480 BC receive
Regency 155.190 TMR receive = (3rd overtone 48.1633) = Bearcat 155.290 BC receive
Regency 460.700 TMR receive = (3rd overtone 50.0000) = Bearcat 460.800 BC receive