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Cobra 139 XLR

Posted: Sunday 16th Dec 2007, 5:25
by captian_radio
Does anyone know which 2 cans that need to be adjusted to change the freq. response for USB and LSB.Usb tx audio is fine but the LSB audio is a bit on the thin sounding side.I have looked on CB Tricks but it does not show any info.Anyone know what these adjustments are?
Tnx Bob

Re: Cobra 139 XLR Off frequency.

Posted: Sunday 16th Dec 2007, 11:17
by Rick
Bob,
It not a can's but a Trimmer Cap's CT4 (USB), CT5 (LSB) and CT6 (AM).

Posted: Sunday 16th Dec 2007, 13:26
by captian_radio
Tnx for the reply Rick,I always look forward to your info.The trimmer caps that you mentioned are used just for aligning the tx freq, when I said that the audio sounded thin I didn't mean off freq,maybe what I should have said is that it does not seem to have as much fullness, sounds a little tinny compared to USB. Isn't there an adjustment on all ssb radios to balance out the audio on tx so that you get and even balance (highs and lows) freq. response on both modes? Like a tunable freq.response in tx audio so that one sideband doesn't differ in tonal quality.Looking forward to your advice Rick.
Tnx Bob

Re: Cobra 139 XLR Off frequency.

Posted: Sunday 16th Dec 2007, 22:36
by Rick
Sorry I did not read it right.
You should align TX and RX to sure of being right.
CT2 (USB) CT3 (LSB).
You need to connect frequency counter to TP9 to do this adjustment as it is easy to get wrong, with the counter on TP9 adjust CT2 for 7.80250 MHz and CT3 for 7.79750 MHz.