the following files you will need to
You need to have Acrobat Reader version 5 or newer installed to view
|Service Bulletin Description||
|The local NOAA weather station is not received.||18RV, 23 Plus, 41 Plus|
|All channels are locked on the same transmit frequency. (R130 burning on 148-series)||148GTLST, 148NWST|
|Tx squeal on 25-series w/SoundTracker engaged||25 Series Radios|
|Squealing & muffled sound on HG mikes||HGM73, HGM75, HGM77, HGM84, HGM84W|
has switched to a different type of potentiometer for the volume and RF
Gain controls. The old potentiometer is round, the new one is square. The
potentiometer mounts on a small PC board. The new potentiometers will not fit
on the older PC boards.
|All 148s with front-mount microphone.|
needle sticks after transmit, and there is no receive. Pushing the
Soundtracker button (if equipped) may restore proper operation.
|All versions of the 29LTD|
switched to a different PLL chip (IC1). The older chip is the 2816,
and the new chip now says 29LTD on it.
of the 29LTD, including models with weather, Soundtracker, and
|Disable Soundtracker||25, 29, and 148 with soundtracker|
when transmitting on sideband. This can occur if the power supply
cannot keep up with the power demands of the transmitter.
|148 GTL, 148 GTL ST, 148 NW ST|
|No transmit power on AM.||148 NW ST|
|Excessive PA feedback||19DXIII|
|Squealing on transmit.||148GTL, 148NWST|
|This document provides a list of part numbers for the LED channel display.||18, 19, 21, 25, 29, 148|
transmit, intermittent receive, intermittent modulation, squealing on
transmit or receive, or other erratic behavior.
|All CB models|
|You can still hear sound from the speaker even when the volume control is turned all the way down.||25 WX NW ST|
|Squealing on receive when using an external speaker.||25 LTD ST|
|Replacing the NB8719 PLL chip with an MMB8719.||148|
|Replacing the Nightwatch power supply module.||All Nightwatch CB models|
|Excessive alternator whine.||All 25s with front microphone connector|
|How to add talkback.||200 GTL DX|
overloads when receiving a strong signal, resulting in distorted audio.
In addition there may be a warble in the modulation when transmitting (which
might be described as a popping sound during transmit).
|Reduced adjacent channel rejection when the Noise Blanker is on.||200GTL|
|Speed-up the echo effect (add reverb).||150GTL, 200GTL|
adjusting the squelch control, sometimes received signals may sound
choppy due to the squelch repeatedly opening and closing.
|The HF50-12F(Q35 and Q40) finals are no longer available.||200GTL|
|The frequency display is not accurate.||
|Modulation may be low with some noise canceling microphones.||200GTL|
|When transmitting, there is sometimes a pop in the modulation.||150 GTL DX|
|Motor boat noise in RX audio.||25 NW LTD|
|Excessive acoustic feedback when transmitting with talkback.||29 LTD SE|
|Adding talkback||CB models 25 and 29 (all versions)|
|The ANT light is coming on even though the SWR is below 3.||CB model 29 (all versions with the ANT light)|
|How to increase the volume of the talk-back.||CB model 29 (all versions with talk-back)|
|How to adjust the talk-back volume.||200 GTL DX with factory talk-back|
|How to adjust the BRT / DIM lamp intensity.||29 LTD with factory blue lighting|
|How to increase the talk-back volume.||150 GTL DX|
|Audio amplifier versions on the 25/29||25/29 Versions|
|2SC1969 substitute for the 148GTL||148GTL|
|No Display on the 29 LX LE||29 LX LE|
Disclaimer: Although the greatest care has been taken while compiling these documents,
we cannot guarantee that the instructions will work on every radio presented.