anyone got info on how to smoth the audio out on ssb sounds very raspy,also has a fixed bias to finals any info..
thanx john
73's
cobra 200 gtl dx ssb problem
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raggatwins
- Newbie
- Posts: 3
- Joined: Friday 21st Apr 2006, 8:48
- Location: uk wales
Cobra 200 gtl dx ssb problem
What size PSU are you using.
Rick.
Rick.
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haans_gruber
- Dead Key
- Posts: 10
- Joined: Thursday 27th Jul 2006, 7:07
- Location: Freehold, Terra Libra
Hi John,
We are working on the pinched SSB audio on the Cobra 200 GTL DX now. We are also somewhat dissatisfied with the SSB audio quality considering this is a Cobra radio. I first believe the power cable is underrated for the output of the radio PA section. I changed mine to 8 guage wire from the battery in the vehicle and shortened the length to my Astron RS 70/M power supply. Which helped in all cases except the SSB pinched audio department.
I have put in a request with Cobra for a remedy/modification as well as a service manual. We hope to be takling this issue in the very near future. We will post any news/modifications here as soon as they are tested.
peace,
haans
We are working on the pinched SSB audio on the Cobra 200 GTL DX now. We are also somewhat dissatisfied with the SSB audio quality considering this is a Cobra radio. I first believe the power cable is underrated for the output of the radio PA section. I changed mine to 8 guage wire from the battery in the vehicle and shortened the length to my Astron RS 70/M power supply. Which helped in all cases except the SSB pinched audio department.
I have put in a request with Cobra for a remedy/modification as well as a service manual. We hope to be takling this issue in the very near future. We will post any news/modifications here as soon as they are tested.
peace,
haans
Re: Cobra 200 gtl dx ssb problem
Used with a good PSU no problem.
Rick.
Rick.
-
haans_gruber
- Dead Key
- Posts: 10
- Joined: Thursday 27th Jul 2006, 7:07
- Location: Freehold, Terra Libra
200 GTL DX - 'Pinched' SSB audio adjustments
- If the SSB audio is muffled and narrow, or 'pinched up' sounding an adjustment of the carrier point may be necessary in order to correct this. The output quality of the SSB audio frequency response is greatly improved by adjusting (T714 - LSB) and (T715 - USB) while simply using another SSB transceiver to monitor the TX audio output of the Cobra 200 GTL DX in the same SSB you are adjusting (with headphones if they are available) If not the feedback tone may be used between the microphones and the speakers of the tranceivers. Zero beat the tone as best you can. Then transmit the signal back to the Cobra 200 GTL DX to check the RX to confirm the TX and RX are aligned with one another. Do this carefully with each USB & LSB making sure the radio is 'warmed up' prior to any adjustment.
Recommendations: For best results perform all work on the 200 GTL into a dummy load if possible. Try to choose an accurate high quality transceiver for the adjusment. Do not use a metal tool to make the adjustments, use ceramic, or nylon/plastic alignment/tuning tools. The metal affects the tuning of the slug/coil and thus the output of the radio TX. Metal can also break the tuning slug requiring replacement.
more info here: http://www.ke4gdx.mine.nu/users/amateur ... TL/Photos/
peace,
haans
- If the SSB audio is muffled and narrow, or 'pinched up' sounding an adjustment of the carrier point may be necessary in order to correct this. The output quality of the SSB audio frequency response is greatly improved by adjusting (T714 - LSB) and (T715 - USB) while simply using another SSB transceiver to monitor the TX audio output of the Cobra 200 GTL DX in the same SSB you are adjusting (with headphones if they are available) If not the feedback tone may be used between the microphones and the speakers of the tranceivers. Zero beat the tone as best you can. Then transmit the signal back to the Cobra 200 GTL DX to check the RX to confirm the TX and RX are aligned with one another. Do this carefully with each USB & LSB making sure the radio is 'warmed up' prior to any adjustment.
Recommendations: For best results perform all work on the 200 GTL into a dummy load if possible. Try to choose an accurate high quality transceiver for the adjusment. Do not use a metal tool to make the adjustments, use ceramic, or nylon/plastic alignment/tuning tools. The metal affects the tuning of the slug/coil and thus the output of the radio TX. Metal can also break the tuning slug requiring replacement.
more info here: http://www.ke4gdx.mine.nu/users/amateur ... TL/Photos/
peace,
haans
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