BCD536HP reference oscillator adjustment

[RFI-EMI-GUY]

Has anyone a clue as to where the adjustment for the reference oscillator is inside the BCD536HP ? Secondly, what is the 1st IF frequency so that I can determine if the LO is on frequency.

 

[KevinC]

IF frequencies are here…

I.F. specifications rarer than..........

I have spent a week trying to locate information on I.F. specifications for the 536 HP. I have searched countless posts about the subject. I usually find the same question I have, but then no specific answer from anyone, and the subject drifts off in the threads. I have tried to work with...

forums.radioreference.com

I suspect the reference oscillator is a soft pot and takes a test mode to access.

 

[RFI-EMI-GUY]

IF frequencies are here…

I.F. specifications rarer than..........

I have spent a week trying to locate information on I.F. specifications for the 536 HP. I have searched countless posts about the subject. I usually find the same question I have, but then no specific answer from anyone, and the subject drifts off in the threads. I have tried to work with...

forums.radioreference.com

I suspect the reference oscillator is a soft pot and takes a test mode to access.

I hope not, unless the test mode is published. Anyway thanks for the link to the data below. I will sniff it out and see how it measures. I did perform an offset acceptance bandwidth test in FM mode and the radio seemed "on freq" - indirectly. But for digital I want it to be dead on. Thanks

-----------------------
From UPMAN (SK)
1st Heterodyne:
25.000-319.995 MHz : Upper Heterodyne 380.75 MHz
320.000-511-995 MHz : Upper Heterodyne 265.55 MHz
758.000-805.995 MHz: Lower Heterodyne 265.55 MHz
806.000-1300.000 MHz: Lower Heterodyne 380.75 MHz

2nd Heterodyne:
25.000-319.995 MHz: Lower Heterodyne 10.800 MHz
320.000-805.995 MHz: Upper Heterodyne 10.800 MHz
806.000-1300.000 MHz: Lower Heterodyne 10.800 MHz

3rd Heterodyne:
All Bands: Lower Heterodyne 450 kHz


Uniden "Big Daddy" Product Ninja

------------------------------------------

 

[techman210]

IF frequencies are here…

I.F. specifications rarer than..........

I have spent a week trying to locate information on I.F. specifications for the 536 HP. I have searched countless posts about the subject. I usually find the same question I have, but then no specific answer from anyone, and the subject drifts off in the threads. I have tried to work with...

forums.radioreference.com

I suspect the reference oscillator is a soft pot and takes a test mode to access.

it’s what has kept me from a SDS radio.

If I have to do this yearly on a Motorola fleet of radios, I’m not touching a scanner that I can’t verify/adjust the master oscillator.

 

[RFI-EMI-GUY]

it’s what has kept me from a SDS radio.

If I have to do this yearly on a Motorola fleet of radios, I’m not touching a scanner that I can’t verify/adjust the master oscillator.

Yeah; I was on an 800 MHz project and found that due to the Coverage ATP being delayed so many times, the reference oscillators on all of the radios had drifted well outside of the NPSPAC tolerance. Apparently the first 18 months the TCXO's age quickly.

 

[Ubbe]

Most modern scanners, as well as most modern 2-way radios, use softpot and there's nothing to mechanically trim any more.
I would like to frequency adjust my 536 and TRX-2 but there's no master oscillator trim in those. It has to be done in service mode.

Crystal scanners usually didn't offer any trims but they used so wide IF filters that it didn't matter if the crystal drifted a couple of KHz and there where no digital systems at that time.

/Ubbe