Cobra 132xlr or 138xlr

[phantom309]

I have a chance to get 1 possibly both of these radios at a fair price.

But not sure which is the better one of the two. I don't mod old radios, but I do rotate them in an out of the base station ever now and then.

Never been a huge cobra fan personally. But hard to pass this deal up.

Just not familiar with the xlr line.

Thanks in advance.

 

[338_MtRushmore]

I would take the 138xlr and run. Great radio if done right. It is typically reguarded as better than the 148/grant by those that know.

 

[phantom309]

Thank you.

 

[phantom309]

Ended up with the 132xlr, the 138 is blowing fuses as soon as you turn it on. He will get it repaired and let me have it for the cost of the repair and the selling price.

 

[loosecannon]

i wouldnt have even bothered with the 132xlr. that one's not even worth fixing.
both of these radios will need to be re-capped before they will work correctly.
LC

 

[ExitThirteen]

132XLR is a bad radio. Has the infamous "double-sided" PCB that has a LOT of solder joint issues. The 138XLR is a far better radio. If the 138XLR is popping fuses, that usually means the polarity diode has gone fault, but that's an easy fix. Both radios would likely need a recap, but in the end you'd have a far more reliable radio in the 138XLR.


~Cheers~

 

[338_MtRushmore]

Doesn't the 138xlr have some sort of speech processing or something?

 

[LeapFrog]

I have read on this forum that the XLR series did have some kind of processing.
I cannot confirm.

EDIT:

CBC SPEECH PROCESSOR
The CBC processor is pretty much a copy of the Uniden speech clipper circuit used in the Cobra "XLR" series of radios as well as others. It is the primary reason that these rigs sounded so loud and clear on the air. The circuits in the AM and SSB models differ in that the SSB units have a low-pass filter following the clipper to clean up objectionable audio harmonics. An excellent explanation of how the circuit works can be found in "Understanding and Repairing CB radios" by Lou Franklin, pages 168-170. The SUPERSCOPE CB640 (also built by Uniden) had this same clipper circuit on a seperate "Mike Amp and ALC board" (Sam's #239 ). I installed one of these boards out of a junk CB640 into my RCI 2950. It REALLY pumped up the audio.

I think that the specs for the voicemax unit selling on Ebay are pretty exaggerated. I just don't see how you can boost the audio power by that many dB without adding tons of distortion. But...the board works, and that's the bottom line. I would really like to see a schematic of the circuit.

- 399

Many "updates & fixes" came out for the 138XLR, take a look here.
You may consider downloading these and saving them, or direct this information to the gentleman's technician so he can address any needed updates.

 

[nomadradio]

The XLR line of radios dates from late '77 to early '79.

Somewhere around the 35 to 40-year age bracket, a radio will cross that line from "repair" to "restore".

They were a decent design in the late 70s. So was the Ford F100 from that era. But sooner or later age becomes an issue even so.

73

 

[phantom309]

I can't complain, the 132 was recapped 3 years ago and I picked it up for $40.

The 138 I'm not sure about. The guy that I am buying the radios from used to live in the Chicago area, but now lives is Tennessee. He is sending the radio to a friend of his that used to work at the cobra plant in Chicago for 20+ years before he retired and opened up his own shop. He supposedly knows these radios inside out and has been their only tech the whole time they have been owns by the seller.

I will be picking up the 138 for $60 plus whatever the repair is.

 

[LeapFrog]

Right on Phantom309!

I have a an example of the board Unit_399 mentioned in his post. (From an old thread.)

The SUPERSCOPE CB640 had this same clipper circuit on a seperate "Mike Amp and ALC board" Sam's #239. I installed one of these boards out of a junk CB640 into my RCI 2950. It REALLY pumped up the audio.

If anyone has interest in creating your own board.
I will help you get some Hi-Res photos, and details.
I am in the process of re-creating this board into a modern kit using KiCad, If anyone wants to be a part of this project, let me know in a PM. Or if you just have interest in a finished board, one day I'll get another thread rollin' on this.

 

[338_MtRushmore]

The XLR line of radios dates from late '77 to early '79.

Somewhere around the 35 to 40-year age bracket, a radio will cross that line from "repair" to "restore".

They were a decent design in the late 70s. So was the Ford F100 from that era. But sooner or later age becomes an issue even so.

73

I didn't realize they were that old, thanks