The Defpom Forum, for RadioMods, S&M Software and Music by The Defpom

I have helped 5 guys in the passed month to get there radios up and running vir the PM on this forum and not a one has express any form of gratitude, is just to much to say thanks.

Rick.

Rick,
Your posts keep me thinking and learning. I really appreciate that. Thanks for posting to this forum ...

See my diagram it may help see how the MB3756 voltage reg works in the Cobra 148 GTL

http://www.cbtricks.com/radios/cobra/148gtl/graphics/cobra_148gtl_sch_redraw.pdf

Rick, Your schematic is the best! Its clear and straightforward! Thanks! I think I may have found an omission on it for your next ...

Yes it should have been R149.
I do know about wire colours from the pot VR402 as this changes from model to model.

Sometimes I think thats done just to confuse people working on the radios. Its the factories little joke. After this great thoughtful discussion I like the way you do it best of all ...

The method I have used as been used for many years with no trouble and as found to be very stable method, if you require more shift with this method I am using just replace the varicap D35 with one which has a ratio of 1.7 to 2.2, the varicap I use is SVC251 or BB909 this will give you a slide of ...

Rick already said to use pin 1 instead of pin 3. Pin 1 runs a constant 8volts, so the answer to your question is YES. Use pin 1.

So of all the ways I've seen to unlock the clarifier on a PC412 148gtl is this then the preferred way and will it give the best performance?
Revised.
1. jumper R175
2 ...

Rick,
I've seen this version on the net. It promises to be centered with +/- 6 kHz of slide and perfect tracking of Tx with Rx. Is it too good to be true? Could you just use pin 1 instead of pin 3 for this version?
Jamie


<<If you do the changes below you will get -6kHz to +6kHz with 0 right in the ...