| Author |
Message |
    
Skullman
| | Posted on Tuesday, October 23, 2001 - 6:57 pm: | 
|
In the CB Tune UP Manual, Master Edition, volume 1, page 51. It lists a power modification for the Cobra 148 GTL that calls for changing the values of "R126(10K)to a 2.2K and R124(10K) to a 4.7K". My question is this, are these 1/4 watt or 1/2 watt resistors? Also it says on page 60 to change the final to a GE-66(10 amp) or NTE-152(7 amp). Has anyone tried these mods? Are there any better ones I might try? Also will these mods work on a 148 GTL made in Malaysia? The book list antoher set of mods for that radio.
Thanks in advance from the Deadman. |
jyd
| | Posted on Wednesday, October 24, 2001 - 8:31 pm: |
|
my friend had them done and it sounded better without doing the mods, |
307
| | Posted on Monday, October 29, 2001 - 6:06 am: |
|
1/4 watt resistors , however it does not really matter because current at this point is null...The modifications work great!
307 |
Skullman
| | Posted on Monday, October 29, 2001 - 8:28 pm: |
|
Thanks 307, I tried it and it really impovred the audio. Makes the stock mic sound like a power mike. |
975
| | Posted on Sunday, March 10, 2002 - 3:25 am: |
|
NO NO NO NO..... do NOT change these resistors!!! They are also part of the AMC loopback circuit. They will cause overdriving of the audio IC!! If you must change them, use 1/4 watt 4.7k ohm resistors for BOTH R124 and R126. If you want more audio, you can do this by increasing the gain on the audio IC by changing the gain determining resistor of the IC. (more resistance, more gain) OR... do not clip R131, or TR-24, add a 1.5K ohm resistor to the middle leg of TR-24 by cutting the trace, and adding the resistor across this trace that was cut. |
Sparkomatic
| | Posted on Tuesday, February 04, 2003 - 12:50 pm: |
|
On the schematics I have, R126 and R124 should be 10K Ohm resistors.......on the 148s and grant that I presently own R124 is actually a 5.6K Ohm.
I replaced R126 with a 4.7K Ohm and R126 with a 2.2K Ohm..........brings up the audio a little bit but then the mic is more sensitive and background noise is increased too. Forget about running a power mic.......with these mods your stock mic sounds awesome. |
Ecarvalho
| | Posted on Sunday, June 15, 2003 - 5:47 am: |
|
I have a 148F GTL and made a slide mod to voicelock. I can center AM and LSB but not USB. I have L59 twisted all the way down and still can only get close to 27.184.3 (channel 19 as example) Is it OK to put a resistor on the potenciometer from center wire to orange wire? I was thinking of a 5koms resistor (black/gray/orange). Please advise! Thanks ed. |
Bigbob
| | Posted on Sunday, June 15, 2003 - 9:48 pm: |
|
add a small choke in series with L59 to give you more range,like a 10 micro-henry.if that makes it worse,use a 10 pico-farad cap instead,preferably a vari-cap. |
Haymaker
| | Posted on Sunday, June 15, 2003 - 9:49 pm: |
|
TRY RE ALING THE RADIO TO FACTORY SPECTS! YOU SHOULD NOT TURN THE COIL, ALL THE WAY DOWN,OR MIGHI I SAY BOTTOM THIEM OUT. MIGHT OF DAMAGED L59 WINDINGS. |
Bigbob
| | Posted on Tuesday, June 17, 2003 - 8:08 pm: |
|
You are correct haymaker you got to be very gentle with those coils,use plastic tuning tools only or CRACK and its all she wrote. |
Lasthighlander
Junior Member
Username: Lasthighlander
Post Number: 18
Registered: 8-2004
| | Posted on Sunday, September 05, 2004 - 11:53 am: |
|
I have a grantxl I did those mods to mine except I used 2 4.7 res`s, it worked out great and I use a rk56 mic clean and clear and loud. |
|
