Cobra 148GTL clarifier help

[KD2GOE]

I need to unlock the clarifier on my 148GTL being in buffalo it gets cold here and makes my 148 drift BAD so it makes talking to more then 1 person bad.. but I didn't want to add any more slide to the clarifier then I need.

I have a Philippines 148 "1992" I think from the SN

The mod I did was remove D52, R44, move the 8v clarifier to fill time 8v's from the PLL 1,000 uF cap.. Then added a 800ohm resistor from the 8v reg to the junction of R174 & D51
now what seems to be happening is TX and RX are not in sync and are off a little.

 

[Robb]

First of all, you must have a bench-type freq counter when unlocking the clarifier if you are going to do it right, because it will throw out of alignment the first oscillator so it will need to be re-adjusted.

Second, if you jumped R175 - it will slide too much.

The standard clarifier range is ~700hz - center to left; or center to right.

Robb:

The following will unlock and keep the standard clarifier range:
Remove D58
Follow the wire (white or green) from R44 and remove the other end from the PC board and connect it constant +8 volts (IC4 pin 3).

I like this method because it keeps VR5 active so that the TX frequency can be adjusted. Pulling D52 - as the other mod on this thread suggests - makes VR5 inactive. And if the radio is off TX freq - probably - you are in a world of hurt. You need VR5 if you want the radio to be dialed in with your frequency counter for alignment purposes.

I use the method - on that page/link I provided - that does't extend the slide range - and doesn't clip D52.
As it also makes it much easier to clarify since it will slide only ~2kc's either way.

http://www.worldwidedx.com/cb-band-cb-radios/49063-cobra-148-gtl-review-6.html

 

[KD2GOE]

i didn't jump R175

i do have a bench top freq counter

are you saying leave R44, The wire that white or green wire soldered to it, the other end gets removed and tapped to constant +8v

 

[Robb]

I didn't say that.

The way I do it is really easy and it allows for VR5 to be adjusted - which is very important in order to keep the radio on freq in SSB mode.

Put D52 and R44 back in. Keep your +8v power (green or white) wire on the '+' end of that 1000uf cap as you have already done. Clip one end of D58. Re-align the first oscillator with your clarifier at the 12 o'clock position and don't forget to adjust VR5 in TX mode. Done.

*Not responsible for work done wrong*
*Put it back to stock if you do not know what you are doing*

 

[KD2GOE]

thanks rob I put it back to stock...

then did the mod you listed it is working now... THANKS!


I have done 3 cobra 142GTL's before and they went with out a hitch I just got some incorrect info on doing the 148

I put this mod in my notes so I wont have any more trouble...