#119

In this video we repair the audio output generator on a Sencore CB42 signal generator.
Manuals:
gokarters.com/s...
Files and repair stuff on CB42:
gokarters.com/s...
Contact Info:
gokarters.com/s...

[@BobHoffmannBHMY]

Thanks for this informative video about the Sencore CB42 CB Analyzer. The concept at the time was to provide the servicing technician of a CB radio to hook up the essential cables to the product, and then conduct troubleshooting tests from the RF input to the power transmitter output to the antenna, with some twists of the appropriate dials. Such was called a "systems approach" for troubleshooting for finding the problem fast, rather than the parameter measurement techniques of Tektronix and Hewlett-Packard instruments of the time. I wrote the operations and some of the maintenance portions of the CB42 manual.

[@ronalddorough604]

i wonta see the video on the rest of the repair i have one of thoes units myself i tried to fix it my self but no luck i find the video verry useful

[@skywire4]

Please add more about CB 42

[@TheRadioShop]

Will do

[@jpires4159]

Very nice

[@TheRadioShop]

Thank you

[@AF6LJSue]

Cool. Good work.

[@TheRadioShop]

Thanks Sue, Always good to see you

[@pineland194]

awesome thank you

[@TheRadioShop]

You're welcome!

[@randelstuckey5494]

This is a very interesting project. I would love to see the rest of the repair if possible.

[@mikesradiorepair]

Definitely do videos on any other repairs on the unit. So few of us that work on this kind of stuff do so there isn't a lot here on the Tube. That unit looks like it's in near mint condition. Many of them you see look like the one you have, well used. I need to dig out some of my spare 1040 and 2040's and rebuild them in case I need them one day. Thanks for sharing.

[@TheRadioShop]

Will do Mike. I searched and nothing on the internet of repairing these. So will get up a few videos on KZbin. One day I want to get a 1040 to play with. Never owned one. I do have 2 2040's with PLL issues I need to repair. Thanks for stopping in Mike.

[@mikesradiorepair]

The Radio Shop If you use the 1040 / 2040 combo you really get to liking them. You can do an amazing amount of diagnostics with just those two pieces and a frequency counter and scope. One thing I recommend is the operating manuals for those two. Even if you don't own the equipment there is a lot of good info in them on alignment procedures, test procedures and diagnostic methods. They spent a lot of time writing them and did a really good job.

[@craxd1]

If one wishes to repair radios, then one must learn how they work, such as how heterodyning works, which is the basis of all radio and TV operation. The ARRL Handbook would be a good place to start.

[@jaybats7865]

Great video Buddy. Looking forward to your next video 👍

[@mellagarde7142]

I really like learning from your videos. I pick up as much as I can with my limited knowledge but your patience and careful descriptions really help me learn bit by bit. Thank you, Buddy. Mel

[@TheRadioShop]

Thank you very much Mel. I am pleased you can find useful information in my videos.

[@MrCherokeewolf]

The Radio Shop hey I have the same model doing almost the same thing. Care to take a look at it?

[@darylynn621]

They are naught special if you keep the scope end as is, but the hand ,wand, end are a strange size. They used to sell them as a. Package for different machines. My 3 yrs old grand son, cut mine experimenting with wire cutters, he is now an Army Ranger.go figger..If you see SC61 CHEAP they are wonderful gifts to starters.

[@call5sam]

I would love to see the complete repair and alignment of this unit. Great stuff!

[@TheRadioShop]

Thanks Sam

[@lylewatts6370]

Yes please show us how to repair the digital readout on the CB42. I agree that when starting out repairing one should learn on the easy stuff first then step up to the more complex radio circuits. Thanks for sharing your knowledge.

[@TheRadioShop]

Thanks Lyle. I have two of these on the bench now.

[@Chuck-U-Farlie]

thank you so much for making this video!!! as you know im a CB42 fanatic, and finally have a fully restored working unit. I can't wait to see more repair videos on this unit. ALSO! please please please do a detailed video on the calibration/ alignment as there are some parts of it that i think i need to see to understand better.

[@TheRadioShop]

Hi brother!. So good to see you. Yes when I get these two units working I will do a full alignment video. Thanks for stopping in.

[@TRXLab]

Good job Buddy! I like this old stuff and the one you have on the bench looks almost like mint condition. Always a joy to follow you along! Take care

[@TheRadioShop]

Thank you Peter. This one is in very good shape. Thanks for following along 73

[@vetterfellow]

I gotta watch this video again, a lot to absorb. Someone couldn't fix that unit and they took it to the best. Love your videos great work.... Angelo

[@TheRadioShop]

Thanks Angelo. Yes a lot happening inside this unit.

[@Sloxx701]

Great video Buddy. I think it's ok to have certain simple test equipment, even if you're just starting you're going to have to get a few things so that you can learn. Hands on is just as important as reading. Multimeters (the first thing you should always get), a cheap scope, soldering iron, hand tools, bench power supply, breadboards, test leads are a few things that I started with years ago. But when you want to specialize and start getting into expensive or obscure stuff, then yeah that comes later. My recommendation if it's a new guy would be to stay away from repairing mains powered/high voltage stuff until you really know what you're doing. Be safe!

[@TheRadioShop]

I agree!. One thing is to pick up equipment and as you learn more then tackle the problems. I know what you mean on the mains powered equipment. New guys need to be aware.

[@rodekglan]

I really enjoyed this video and would like to see more of the repair or this unit. I really enjoy all your video and have learned a lot watching them thanks and keep up the good work.

[@TheRadioShop]

Thanks Jeremy. I have two of these on the bench;-)

[@injoelsgarage3934]

Hey Buddy, yes please continue with the video series repairing this unit. Awesome job. Thank you for your time and sharing. Joel

[@TheRadioShop]

Thanks Joel.

[@dennisqwertyuiop]

good video repair when they first came out I bought one new I think my was 50 channel also bought new CB41 power swr meter it had a remote head so you could run meter away from antenna,, thanks for bringing back memory

[@TheRadioShop]

Thanks Dennis. The guy I worked with many years ago in a cb shop bought the CB42 and the 41 power meter. They were great working units back then. Thanks for commenting.

[@pierrelataillade7564]

Actually Buddy I don't know how I missed this vid, but i'm glad that i found it ..... great job on your diagnostic, I see now why it pays to have good diagnostic equipment. thanks...

[@toddanonymous5295]

Another great video Buddy . You are always interesting and informative . Thanks for all your efforts.

[@TheRadioShop]

Thanks for those find words Todd. Appreciate it.

[@PapasDino]

Oh yeah...keep going! Sometimes simply reseating an IC will cure a total or partial failure...had that happen just the other day in a old Heathkit HW-8 QRP rig - the sound thru the audio filter IC was crackly and popping it out, a little DeOxit on the pins, and slapping it back in was all it needed. 73 - Dino KL0S

[@TheRadioShop]

Good tip Dino. You know sockets have pros and cons. Replacing ic's can be hard on circuit traces. Sockets help that problem. But then sockets can corrode and get tarnished. Must be cleaned or replaced. Would be nice if all of these were in sockets. Would make testing a lot easier. Thanks for commenting my friend.

[@chuckcarabelli7746]

Good job Buddy, I'm learning new stuff for the ole' mind with each new video you make, Thanks!! :)

[@TheRadioShop]

You are very welcome Chuck. Thanks for watching my friend.

[@jerryblood9554]

Thanks Buddy. Nice video.

[@TheRadioShop]

Thanks Jerry.

[@davidknight3643]

Yes please I would love to see more

[@TheRadioShop]

Thanks David, I will be restoring one of these soon.

[@jameslane4206]

Thanks so much and continue. Mine does the same with the display. The if gen works but cb pll is stuck on 27mhz on all 40 channels. Jim KA4BVT

[@TheRadioShop]

Thanks Jim. looks like your PLL is running free then. We will get into that on my unit in the future.

[@Echapm40]

love your videos, of course we want to see the rest. And the FT-101 series, hope you can get back that that soon. I picked up the matching scope at Dayton that I need to go thru.

[@TheRadioShop]

Cool deal eric. I will try and get some more videos on those soon.

[@TheDefpom]

In the video the counter is showing 8's, if it is like that in person too, then I would be suspecting blown output drivers, it likely will be multiplexed, so that could cause it to look like that, MHz led probably blown

[@TheDefpom]

I am just starting to look at the diagram, it is multiplexed, in two blocks of 3 digits, and a single

[@TheRadioShop]

Yep, all 8's at random. You can turn the unit off and back on and at times it will change. Sometimes random numbers across the display, every segment showing something. Cycle power and it will change or go back to 4 8"s.

[@TheRadioShop]

Correct. I am thinking output drivers could be bad.

[@TheDefpom]

The Radio Shop - if it is supposed to show 7 digits all the time, then it could be a clock/latch issue.

[@TheRadioShop]

Yes it is 7 digits. Going to check clock and latch today.

[@bundylovess]

Nice job buddy big thumbs up

[@TheRadioShop]

Appreciate that and thanks for watching.

[@bryanhorne1979]

I just picked up a CB42. Any idea where I can get the test leads for it? Or is there some way to make my own?

[@TheRadioShop]

Not really anything there that cannot be made. mostly just jumpers and there is a speaker box for mic test.

[@cuban9splat]

I agree with chuck carabelli below, Buddy. I too am learning new stuff for my antique mind with each video you publish. Good job. Thank you. 73 DE K7RMJ Frank

[@TheRadioShop]

Thanks Frank. I am please folks can learn from me. Thank you for watching.

[@poduck2]

Did you ever do more videos on this? I have one of these, and was curious to see more about them.

[@TheRadioShop]

Not as yet. I do have one coming that I will working on.

[@seravenerdi]

How would this perform as a strictly AM/ MW receiver with a loop antenna ?

[@kardeef33317]

Great video. Thx :)

[@TheRadioShop]

Thanks

[@eddywainy7727]

Buenas tardes amigo me podrías ayudar con pdf de manual de servicio de monitor de servicio motorola 2660

[@joereeser3810]

Hi Buddy. First of all love your videos! I have a Sencore CB49 that's very clean but seems the SG function works but doesnt have a real strong output. I'm thinking it may need looked at for overall functionality, would this be something I can send to you for evaluation? How can I contact you?

[@peternewman958]

Hello Buddy great video mate, certainly looking forward to the next instalment like everybody else mate. Have always liked these but freight is the killer down to OZ. Keep up the excellent work Buddy.

[@TheRadioShop]

Thanks Peter. Yes these are heavy units and shipping is a deal breaker.

[@danielrine3103]

Hi! Great video, you are truely knowledgeable in this field of electronics. Just a question, I am fairly new to restoring vintage electronics, and I have a lot of Eico units, a 348 audio generator, the Eico 324 RF generator and my newest piece an Eico 147A signal tracer, these units are in very good condition and all work very well. What is your throughts on these for working on tube radios mainly the All American Five? Thank you kindly for any thoughts in the Eico brand... Have a great weekend...

[@TheRadioShop]

Thanks, sounds like you are set up to work on those types of gear, all you need now is a VTVM.

[@dougmcartin3881]

That's a good question Buddy. Was that socket added later by a repair tech or was it factory installed as something that they thought might be a part that would be a common failure and easier for a quick factory repair. Wonder if you looked at the soldering underneath, that would tell the tale. Always interesting stuff and always good to change it up. Have a great holiday weekend Buddy, get some more of those ribs on the grill. ATB Doug.

[@TheRadioShop]

I look under the board and see that the socket has been added. And looks recent as the flux is still tacky. I have seen quite a bit of these units and never seen a socket from the factory. Yes need to grill some more ribs! Thanks

[@danterossi6180]

hi mine reads a wrong frequency, for example I put on ch1 it reads 62.5 hz and so on. could you give me some help? Thank you

[@TheRadioShop]

Is that showing on the counter or at the RF jack?

[@danterossi6180]

@@TheRadioShop I connect the radio example I put on ch1 then set the sencore cb42 on ext freq. I send the radio on carrier and it reads the wrong frequency. another example I set the sencore on rf-if gen the output is correct based on the set channel of the generator but the displayed frequency is wrong

[@danterossi6180]

if you leave me an email I can send you a video. Thank you

[@DonDegidio]

Buddy, Please continue with a video of the repairs. 73 WB3BJU

[@TheRadioShop]

Will do Donald. Thanks

[@drjack1000]

yes yes show more and also sencore VA 48

[@josephriffle124]

I just bought two of these units , neither work. I need a service manual.Please contact me with some options

[@TheRadioShop]

They are on my website. gokarters.com/smf/index.php?topic=2398.0

[@darylynn621]

I would like to find repair parts for the probes for my SC61,MOSTLY THE TIP ACCESSORIES, any one got any scraps? What did you mean "Smoked Then?" I can't think with out my pipe.

[@TheRadioShop]

My probes have gone bad. I like to get some replacement. But man those are high dollar!

[@richardburwell6111]

I have the users manual, service manual, schematics, parts list and calibration guide on pdf, if anyone needs them.

[@TheRadioShop]

Thanks for listing that