Cobra 148 MK2 10Khz off All Bands

[currentstatus]

I* have never seen the manual for this radio. are you sure they did not make an error in the manual. most radios I have ever worked on the usb is
is the higher version 10.6975 and LSB is 10.6925. I have seen the sams book misprint on a few radios a few times.just a question since I have never seen this radio. USB is normally the higher reading. take a look at this.

Thanks for pointing that out.. I've swapped over to Lou Franklin's alignment procedure. In Franklin's documentation the carrier osc offsets are still USB: 10.6925 & LSB: 10.6975. So is this correct?

[sonoma]

try reversing the freq and see just what happens. like in my 1st post I have always seen the lower freq on LSB and the higher freq on USB.
just try it and see if it makes the radio work as it should.

[currentstatus]

try reversing the freq and see just what happens. like in my 1st post I have always seen the lower freq on LSB and the higher freq on USB.
just try it and see if it makes the radio work as it should.

Ok but remember this 10Khz shift is throughout the radio.. AM/FM included. Wouldn't that suggest something more akin to a problem at the PLL stage?

[cb4ever104]

It should be 10.6925 on USB and 10.6975 on LSB.

[sonoma]

here is an example of what I was talking about. look at the L20 and L21 alignment on this radio. I have never seen this radio before since they are very rare here in the US. it was just a thought.

http://www.cbtricks.com/radios/galaxy/d ... ll_adj.htm

[sonoma]

also check the transister for TX. do not have a schematic for it but have seen the TX trans going bad and causing this . should be tr30,tr31, tr32 or tr33. could be one of them bad throwing it off 10kc. just guessing at what trans is in this radio. I think tr33 was one I have seen throw it off freq.

[cb4ever104]

it was just a thought.

I've triple checked it with other Uniden and Galaxy models , and it's the way I stated above .

Cheers

[sonoma]

current status is saying he can not lock on the 16.000 freq. was reading on page 3 that they will not adjust so not sure what it is actually called for on the cans around L21. the L38 etc cans adjust in reverse as mentioned USB has the lower freq and then LSB has the higher freq. wish I could find a manual for this radio on line. found a 148gtl dx late version but not the MK2 version he has.
secret cb has the late version on it but does not sound like what he has.

[cb4ever104]

found a 148gtl dx late version but not the MK2 version he has.
secret cb has the late version on it but does not sound like what he has.

Hi . The Late version is the mk 2 . The early version being the mk 1 .

Cheers

[currentstatus]

I think it's something to do with that EPROM board, there must be a component somewhere which is lifting it by 10Kcs. Something that's left over. For the life of me I can't find it.. I've tested loads now but.. nothing stands out. Wish I had another 148 MK2 to compare.

Right at the beginning of this thread "ROTEL240" mentioned about a Black Spirit ?? Is that an EPROM board.. or a person? Where can I get more info on this.

Also I'm in contact with Tony at Spectrum Comms.. waiting for him to spread some light on it.

[currentstatus]

Black spirit is you man to solve your problem

Who is that man? Where can I find him..

[cb4ever104]

Something that's left over. For the life of me I can't find it.. I've tested loads now but.. nothing stands out. Wish I had another 148 MK2 to compare.

If the frequency at TP3 is correct , as you said it was , then I've no idea . Because after that all you have is the 10.695 mixer and amplifier .

Sammy

[cb4ever104]

Who is that man? Where can I find him..

Just do a member search on the forum .

BS.JPG

[astradyne]

Who is that man? Where can I find him..

Just do a member search on the forum .

BS.JPG

Indeed. If anyone can resolve the issue with your 148 it's Nick. A very skilled and respected member of TM1.

[Kaliphan]

Put it on FM, CH1, low, set KC/Clarifier to centre, measure the voltages on PLL pin 17-9, measure the frequency on PLL Pin 2.

Repeat for CH1 Mid and Hi.

Post the results here.