• You can now help support WorldwideDX when you shop on Amazon at no additional cost to you! Simply follow this Shop on Amazon link first and a portion of any purchase is sent to WorldwideDX to help with site costs.

Black Book Of CB Linears?

V8Vega

Active Member
May 15, 2005
111
5
28
Phoenix Az.
Does anyone have this book? I'm thinking about buying it, but I want to make sure it not only has the schematic, but also has the parts list for my Thunderbolt 305.
 

There's no parts list, but here is a schematic:
Thunderbolt 305
Thanks...I have that schematic, but am not educated in electronics. The variable power pot doesn't work anymore and I want to replace it with a rotary switch that will accept the stock knob to keep her looking mint. I was looking at this switch, but am not sure if it is suitable for this application. When I find a switch, I will then try to figure out what resistors and other parts I will need for the Hi/(Med?)/Lo output.
Switch: ROTARY SWITCH ,3P3T , NS - eBay (item 220685418372 end time Dec-18-10 18:45:24 PST)
 
Thanks...I have that schematic, but am not educated in electronics. The variable power pot doesn't work anymore and I want to replace it with a rotary switch that will accept the stock knob to keep her looking mint. I was looking at this switch, but am not sure if it is suitable for this application. When I find a switch, I will then try to figure out what resistors and other parts I will need for the Hi/(Med?)/Lo output.
Switch: ROTARY SWITCH ,3P3T , NS - eBay (item 220685418372 end time Dec-18-10 18:45:24 PST)

For someone who is not "educated in electronics", the repair/ modification that you want to install is kinda like re-inventing the wheel but, when you get finished, your "wheel" will not be round.

I would strongly recommend that you find a 10,000 ohm (10 Kilohms) potentiometer and replace it as the circuit was designed to operate.

The 10K pot acts as part of the Grid-leak / bias resistor system for the driver tube; to replace that pot with fixed resistors, you would have to at least temporarily install a variable resistor (pot) and measure the values where the wattage output is where you want it for "Hi-Med-Lo". Then, you would have to de-install the pot and put the switch in with the resistors hanging off of it; is it worth it?

I believe that the ability to control your amount of output in a variable manner is much better than the "I'm gonna flip the switch and go to the 'Next' stage" concept.

However, YMMV.

.
 
  • Like
Reactions: n9nrm
The thing has had virtually no use! It's as if it went bad from sitting if that's possible.
I see some electrolytic caps in the schematic. Those do, and probably have, derogated just by sitting.
Good luck with your project!
 

dxChat
Help Users
  • No one is chatting at the moment.
  • @ BJ radionut:
    I am beginning the packing process...XENIA bound Going "Lite": this year....2 items for sale...Rig #1 = FT-920/Gud to Ex condition/Hand Mike/pwr cord/manual (NO BOX) ... #2 = My 1 owner FT-950....EX condition...Original Shipping Double Box/Factory Manual/Never used hand mike...Booths 9107-9111...Ya'al come by say hello...
  • @ BJ radionut:
    Incoming Region Produces X3 Solar Flare
    May 15, 2024 @ 14:55 UTC
    Another major solar flare, but this time from an active region just beginning to turn into view off the east limb. It is possible that the group responsible is old AR 3654 from the previous rotation. The latest flare, an X2.99 event just peaked at 14:38 UTC (May 15). Stay tuned
  • @ ButtFuzz:
    Everything is El Dead-o. Joy!
  • @ ButtFuzz:
    Please advise me to what is a good replacement mic for my SR-497HPC... Answer: 497 is "wired like Cobra", so many choices available. That radio does not need a power mic, so purchase a stock "coffin style" mic with a decent cord, like the ones that Astatic uses. The Superstar DM-507 is my go-to. https://www.ebay.com/itm/3050474478...adANq91JSiEEnz8EGqPJRBloTgEyaVsBoCtoMQAvD_BwE $12.99 + .99 cent shipping.