I think I may have some bad transistors upfront. I looked at the data sheet for the transistor c1675 and I was using the wrong pin out on the HFE meter. I removed a transistor from a different location and got a value of 69, slightly lower than the middle range specification. I then pulled this transistor from the front of the radio in the vicinity of where probing with the multimeter produced amplified sound. This transistor did not have an HFE value. So now to my question. Your advice about the cap replacement was to do a few at a time and then check the radio. Would you recommend the same approach? Replace one transistor and then check the radio. Then repeat etc or would that jeopardize the new transistor. The other question is would it be better to just replace all of the transistors? Thank you for all of your help.
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Smokey 23 channel troubleshooting no tx/rx
- Thread starter Champo
- Start date
I'm going to resolder all of the connections that I touched with flux this time rather than relying on the flux in the solder. Hopefully I can get it back to the original condition, and if so, I'd like to touch base with you again Sunbulls if that is alright? Thank you again for all of your help.
A couple of things......
Have you had any success in contacting that individual that had the schematics? That would help immensely!
If you have so stated... I just missed it... do you have any test equipment? MultiMeter? Scope? Frequency counter? Signal Tracer? When you are fighting a dead one (especially when it worked at one recent time!)... you need to check basics.... are oscillators working? Are all power supply nodes up? Are switching circuits swithching (Rcv and TX) ? Are mixers mixing and working....
You have to kind of "go from the ground up" and it takes some equipment to do that.......
UNLESS you happen to find something like a bridged solder joint that is holding something down......
Have you had any success in contacting that individual that had the schematics? That would help immensely!
If you have so stated... I just missed it... do you have any test equipment? MultiMeter? Scope? Frequency counter? Signal Tracer? When you are fighting a dead one (especially when it worked at one recent time!)... you need to check basics.... are oscillators working? Are all power supply nodes up? Are switching circuits swithching (Rcv and TX) ? Are mixers mixing and working....
You have to kind of "go from the ground up" and it takes some equipment to do that.......
UNLESS you happen to find something like a bridged solder joint that is holding something down......
Regrettably just a meter. I did email the club that the post was on but I have not yet heard back. He has, or did have, a ham license so I might look up his info and try to contact him directly if all else fails. I'm going to try to go back to the beginning before I got in over my head and screwed the pooch. I made several mistakes in retrospect and I have to believe that the fact that it worked before I messed with it minus the modulation leaves me to conclude my poor soldering skills are to blame. All of the original caps tested good after being removed so I think I have a cold solder joint on the board unless I damaged something in the process of removing and reinstalling caps. I cleaned the board last night, which I failed to do the first go around, so I'll post a pic of the solder side of the board. Perhaps you can help point out potential solder issues. I've ordered a desoldering gun that way I don't have to rely on wick as well as flux so I'm not only relying on the flux in the solder. If by some miracle I can get it back to the condition it was in originally then I think troubleshooting the modulation issue will be a breeze...fingers crossed!
At this point.... you may have already done it.... but I would consider doing it again....
If you have a magnifier, magnifying glass or even a cheap loupe (
https://www.harborfreight.com/5-piece-loupe-set-98722.html ).....
go over every single cap position that you changed and look for any sign of bridging. It literally takes ONLY a "whisker's width" of anything to connect adjacent pads....and "boom" something critical doesn't work.
Another curiosity.... as you look the board over... top and bottom.... are there any sticker tags or even painted on markings that suggest a "board part number"? So many "off brand" radios were most likely "contracted" from a mass builder. The way Uniden built chasses for many brands of radios...... and the boards usually had markings.
Do you see anything like that?
If you have a magnifier, magnifying glass or even a cheap loupe (
https://www.harborfreight.com/5-piece-loupe-set-98722.html ).....
go over every single cap position that you changed and look for any sign of bridging. It literally takes ONLY a "whisker's width" of anything to connect adjacent pads....and "boom" something critical doesn't work.
Another curiosity.... as you look the board over... top and bottom.... are there any sticker tags or even painted on markings that suggest a "board part number"? So many "off brand" radios were most likely "contracted" from a mass builder. The way Uniden built chasses for many brands of radios...... and the boards usually had markings.
Do you see anything like that?
Here is another. Most of the caps were in this region. Some brown areas are bridging potentially. I also see a spot that is only partially soldered and needs a do over.
Attachments
Interesting........ focusing on "ACT 1914" I came up with this.....
url: https://www.justradios.com/cbschematics.html
I found (way down the list, under the brand name Romar)
ROMAR
Act-1914 (Code 15206)
I can't swear it is what you are looking for......but at least it is a chance......
It might be the same board by a different branding.....
justradios.com is a fairly well known website...... been around for a long time....
url: https://www.justradios.com/cbschematics.html
I found (way down the list, under the brand name Romar)
ROMAR
Act-1914 (Code 15206)
I can't swear it is what you are looking for......but at least it is a chance......
It might be the same board by a different branding.....
justradios.com is a fairly well known website...... been around for a long time....
Also interestingly..... SAMS lists the Romar ACT-1914 as being in CB Photofact #104.
The web site shows it.....but it is not available for download...which would mean that you would have to order it. it is around $22 from them for the one radio.....
You might be able to find CB-104 on Ebay or someplace cheaper in paper.....
AND perhaps if someone on here happened to HAVE CB-104 they could look it up for you and SEE if it appears to be the same chassis!
THIS COULD PAY OFF.......
The web site shows it.....but it is not available for download...which would mean that you would have to order it. it is around $22 from them for the one radio.....
You might be able to find CB-104 on Ebay or someplace cheaper in paper.....
AND perhaps if someone on here happened to HAVE CB-104 they could look it up for you and SEE if it appears to be the same chassis!
THIS COULD PAY OFF.......
Okay....I just put up a brand new thread...hopefully to get some attention....to see if anybody might have CB-104 to check for you.
IF THIS PLAYS OUT...... Lookie here.....
$6.50
https://www.ebay.com/itm/SAMS-PHOTOFACT-CB-104-DECEMBER-1976-CB-RADIO-SERIES-/360208570266
IF THIS PLAYS OUT...... Lookie here.....
$6.50
https://www.ebay.com/itm/SAMS-PHOTOFACT-CB-104-DECEMBER-1976-CB-RADIO-SERIES-/360208570266
Same manual CB-104 and there is another listing for a Beta brand CB with a model number ACT-1914.
My bet is....... SAME CHASSIS.... used in THOSE TWO brands..... but is ALSO the chassis for the Smokey 23.
My bet is....... SAME CHASSIS.... used in THOSE TWO brands..... but is ALSO the chassis for the Smokey 23.
I really appreciate all the help. I'm pretty sure you knocked it out of the park! If no one hits you back I'll pick it up on Ebay. Definitely worth the gamble. Did you happen to see any questionable solder areas by chance? Specifically in the magnified pic?