Search found 22 matches

by rockhavenradio
Monday 28th Sep 2009, 2:47
Forum: CB Radio Repair and Troubleshooting
Topic: Galaxy 959
Replies: 5
Views: 3647

Re: Galaxy 959

4558 was bad. ssb tx shows a substantial increase in average power, pep power remains the same.
by rockhavenradio
Wednesday 23rd Sep 2009, 6:45
Forum: CB Radio Repair and Troubleshooting
Topic: Galaxy 959
Replies: 5
Views: 3647

Re: Galaxy 959

Working on a dx959...the mic amp chip (4558) output is noisy when cold...better when hot, but not good. 4558 on order, will post results.
by rockhavenradio
Saturday 1st Aug 2009, 6:21
Forum: Tech Area
Topic: Cobra 200 GTL DX...some issues
Replies: 0
Views: 1345

Cobra 200 GTL DX...some issues

Roger beep...beeps on key-up and un-key.
When radio is hot: in ssb mode...100 watt carrier, no tx audio/AM mode 100 watts, no tx audio.
Anyone?
by rockhavenradio
Thursday 12th Mar 2009, 5:02
Forum: CB Radio Modifications
Topic: My President Washington Wide AM Receive Mod
Replies: 1
Views: 1455

My President Washington Wide AM Receive Mod

This is a modification I came up with as I was unhappy with narrow receiver bandwidth in the President Washington operating AM mode. I have successfully used this simple mod on several radios with this circuit board. I would like to see some other ideas or comments on improving AM mode operation for...
by rockhavenradio
Thursday 26th Feb 2009, 10:51
Forum: CB Radio Alignments
Topic: Alc on the Superstar 3900 question
Replies: 3
Views: 2912

Re: Alc on the Superstar 3900 question

I adjust the ALC while monitoring the output waveform on an oscilloscope. Turning the ALC up too much will result in distortion. Are you useing a PEP watt meter?
by rockhavenradio
Tuesday 27th Jan 2009, 14:47
Forum: CB Radio Repair and Troubleshooting
Topic: 148gtl (4pin)
Replies: 42
Views: 21947

148gtl (4pin)

The 148 GTL series are all similar. 3 pin regulator or otherwise. I also had 2 in. One had a bad 8.3 volt rx switch, TR44 and a shorted audio amp TR41. No rx and poor am tx audio. the other was no rx...cold solder at c175. This one also suffered form poor quality construction requiring reinstallatio...
by rockhavenradio
Tuesday 27th Jan 2009, 14:15
Forum: CB Radio Repair and Troubleshooting
Topic: 148gtl (4pin)
Replies: 42
Views: 21947

148gtl (4pin)

This alignment procedure fits the 148 D china radio
by rockhavenradio
Saturday 24th Jan 2009, 11:26
Forum: CB Radio Repair and Troubleshooting
Topic: 148gtl (4pin)
Replies: 42
Views: 21947

148gtl (4pin)

The service manual is on cbtricks.com...Look for :cobra_148_gtl_sm_pg01_pg15.doc
by rockhavenradio
Saturday 24th Jan 2009, 11:19
Forum: CB Radio Repair and Troubleshooting
Topic: 148gtl (4pin)
Replies: 42
Views: 21947

148gtl (4pin)

your green rx led is lit?
by rockhavenradio
Saturday 17th Jan 2009, 3:12
Forum: CB Radio Repair and Troubleshooting
Topic: 148gtl (4pin)
Replies: 42
Views: 21947

148gtl (4pin)

Voltage on collector of TR44 should be 8.3 volts during receive. This is a receive only voltage.
by rockhavenradio
Friday 9th Jan 2009, 1:55
Forum: CB Radio Repair and Troubleshooting
Topic: 148gtl (4pin)
Replies: 42
Views: 21947

148gtl (4pin)

Good luck with the radio.
Maybe there are some others out here with some better input.
Later.
by rockhavenradio
Thursday 8th Jan 2009, 5:42
Forum: CB Radio Repair and Troubleshooting
Topic: 148gtl (4pin)
Replies: 42
Views: 21947

148gtl (4pin)

148 D Schematic...It's labled 148 F on the top. They said the 148 E is exported to Mexico, and the 148 D is the Domestic version...Don't know what the 148 F model is. This is What Cobra sent me when I asked them for the 148 D, china radio.
by rockhavenradio
Wednesday 7th Jan 2009, 13:17
Forum: CB Radio Repair and Troubleshooting
Topic: 148gtl (4pin)
Replies: 42
Views: 21947

148gtl (4pin)

Sorry, about that...I posted too soon...so disreguard. I was thinking about a different radio. Some radios use a seperate local oscilator for am. I'll look into getting that file to you.
by rockhavenradio
Wednesday 7th Jan 2009, 3:17
Forum: CB Radio Repair and Troubleshooting
Topic: 148gtl (4pin)
Replies: 42
Views: 21947

148gtl (4pin)

I recently worked on the same radio, "148 D"
I have the schematic of that radio.
Cobra sent it to me a few months ago.
If you need a copy, let me know how I can get it to you.
by rockhavenradio
Tuesday 6th Jan 2009, 15:43
Forum: CB Radio Repair and Troubleshooting
Topic: 148gtl (4pin)
Replies: 42
Views: 21947

148gtl (4pin)

Is the no rx symtom on ssb and am?
If no am only rx, 7.345 LO?
by rockhavenradio
Tuesday 6th Jan 2009, 15:28
Forum: CB Radio Modifications
Topic: kenwood ts-120s
Replies: 1
Views: 1253

kenwood ts-120s

Replace 10 meter band local oscillator crystals?
by rockhavenradio
Thursday 18th Dec 2008, 3:36
Forum: CB Radio Modifications
Topic: Cobra 19 Plus Channel Change Mute Disable
Replies: 0
Views: 1301

Cobra 19 Plus Channel Change Mute Disable

When adjusting channels or "scanning the band" with my Cobra 19 Plus, the receive will mute briefly per one press of a channel button, or stay muted when holding a channel button down. Removing D6 will disable this muting feature and allow "scanning the band" without waiting for the receive to open ...
by rockhavenradio
Monday 22nd Sep 2008, 13:27
Forum: CB Radio Modifications
Topic: How many have done cobra final upgrade here , does it work
Replies: 24
Views: 17717

So, Dodgem250, what are the reasons a mosfet final in a cobra 29 won't work?
by rockhavenradio
Tuesday 16th Sep 2008, 14:01
Forum: CB Radio Modifications
Topic: Cobra 29XLR: 5 kHz step mod?
Replies: 1
Views: 1618

Cobra 29XLR: 5 kHz step mod?

I reprogrammed the pins on the 858 chip to give the 5 kHz channel increments. On frequencies below CB channel 1, 26.965, in the 5 kHz mode, there is a 2500 Hz tone on both TX and RX. The amplitude is less than 1% audio. The other frequencies do not have this. The 5 kHz channels above 40 are fine. Ha...
by rockhavenradio
Saturday 9th Aug 2008, 10:18
Forum: Wanted !
Topic: President Washington/Cobra 138/9XLR Replacement Relay?
Replies: 3
Views: 2333

No luck on those sites Rick. Jim, I am looking for about 10 new ones.
Still looking. Thanks!
by rockhavenradio
Monday 4th Aug 2008, 15:20
Forum: Wanted !
Topic: President Washington/Cobra 138/9XLR Replacement Relay?
Replies: 3
Views: 2333

President Washington/Cobra 138/9XLR Replacement Relay?

I am looking for replacement relays for the 858 PLL chassis like the President Washington.

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