I have an old side mic 29ltd classic that is original and unmod"d. The radio will power up but has no tx or rx. When powered up I can key /unkey the mic and see the tx/rx light change, but the needle in the meter does not move when radio is dead key or when speaking into the mic. Also I do not hear anything when connected to antenna and radio has little noise/static coming out the speaker. I plugged in an external speaker and switched it to PA mode and the PA works. One other thing I noticed is that if I disconnect the coax/antenna and key the mic the the rx/tx light changes but the antenna warning light does not come on. Any help and suggestion would be appreciated.
Tuesday, 01 January 2013, 15:22
Did little more checking and hooked radio up to a PDC 7000 meter. Set the meter ( lowest scale) to check the power from the radio and when I key the mic the PDC 7000 meter does not show any power .
29LTD Classic no tx/rx
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TheCBDoctor
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Hi awz71,awz71 wrote:I have an old side mic 29ltd classic that is original and unmod"d. The radio will power up but has no tx or rx. When powered up I can key /unkey the mic and see the tx/rx light change, but the needle in the meter does not move when radio is dead key or when speaking into the mic. Also I do not hear anything when connected to antenna and radio has little noise/static coming out the speaker. I plugged in an external speaker and switched it to PA mode and the PA works. One other thing I noticed is that if I disconnect the coax/antenna and key the mic the the rx/tx light changes but the antenna warning light does not come on. Any help and suggestion would be appreciated.
Tuesday, 01 January 2013, 15:22
Did little more checking and hooked radio up to a PDC 7000 meter. Set the meter ( lowest scale) to check the power from the radio and when I key the mic the PDC 7000 meter does not show any power .
If the indicator shows the radio going into transmit mode, then the PLL circuit is working. If you have a shorted Final that would cause the Receive to be loaded down. Try replacing the final; you may cure two problems at the same time. If the PLL was out of lock the Tx indicator would not turn Red. Under some circumstance you will find the Final would transmit 455 KHz off frequency. I don't think this is your problem because you would see power when keying; it would just be 455 KHz off.
Respectfully as always,
Rick
Rick
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awz71
- 4 PILL USER
- Posts: 39
- Joined: April 16th, 2008, 1:15 pm
CBDoctor thanks for the info. This is an older Cobra 29ltd that was made in Tiawan. The tx/rx light does change when the mic is keyed and unkeyed. When I turn on the radio I do hear some static coming from the speaker when the volume is increased. Looking at the final I can see that it has C2029/1 on it . What can I use for a replacement final?
Saturday, 05 January 2013, 13:43
Can the final be replaced with a 1969 final ?
Saturday, 12 January 2013, 20:35
Found some info on CBtricks and did some checking on the radio. From the info it says to check D19 for 5 volts. I checked D19 and I am only getting 3.0 volts. Then at the junction of D19,R124 and R98 for 5 volts and I am getting 1.24 volts.
Just trying to learn and any further suggestion would be greatly appreciated
Wednesday, 16 January 2013, 15:56
I finally got the radio to working with the help from TheCBDoctor. Anyone needing help I recommend that you contact him as he can walk you through testing out to find the problem.. Rick is the one to contact for anyone that is wanting to repair their radio there self. Be sure and check out his website as he is a sponsor here and he also building a new website [Please login or register to view this link]
Saturday, 05 January 2013, 13:43
Can the final be replaced with a 1969 final ?
Saturday, 12 January 2013, 20:35
Found some info on CBtricks and did some checking on the radio. From the info it says to check D19 for 5 volts. I checked D19 and I am only getting 3.0 volts. Then at the junction of D19,R124 and R98 for 5 volts and I am getting 1.24 volts.
Just trying to learn and any further suggestion would be greatly appreciated
Wednesday, 16 January 2013, 15:56
I finally got the radio to working with the help from TheCBDoctor. Anyone needing help I recommend that you contact him as he can walk you through testing out to find the problem.. Rick is the one to contact for anyone that is wanting to repair their radio there self. Be sure and check out his website as he is a sponsor here and he also building a new website [Please login or register to view this link]
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Jon_001
- Mud-Duck Sr.
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- Joined: February 19th, 2013, 8:35 pm
Would you mind posting the solution?
