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A radio that's configured to use an electret mike is sending a DC voltage out the audio wire. If you can choose dynamic from the radio's setup menu, this might fix it. The SSK's cartridge is dynamic, but its output is amplified. The DC voltage feeding out of the radio upstream into the mike...

Stryker isn't set up for an electret mike, is it? Just a shot in the dark. 73

My antenna switch grounded the unused side of the antenna. Didn't seem to affect the side that was in use. 73

Cool! Turns it into a 2510. Complete with the low-level AM modulator and quirky control of the carrier. Just be sure to change the parts in the sideband AGC to make the receiver sound like a 2510. Sorta. Very ambitious and functional upgrade. 73

I want to spoof my caller ID so the phone displays "Hey, it's me. Pick up!" 73

Needs to be a bit above 3 Volts. 73

The side with the 3-legged transistors is the power supply rectifier and regulator. The black transistors are all wired in parallel, except one. The opposite-side heat sink contains the actual linear. Basically a 12-Volt mobile linear with a regulated power supply on the opposite side and the...

Or maybe just suck the solder off the collector pad and push the lead into the center of the hole. Isolating one lead is less work and risk than removing the part altogether. 73

It's a quirky circuit. The diode D9 is wired to rectify the modulation audio and feed a negative DC voltage into C144. Makes grounding the positive side necessary. The filtered negative DC voltage goes to the base of the PNP transistor just below in the diagram. The transistor's emitter is...

Yep. A fixed resistor with an electrolytic capacitor in parallel with it permits the full peak audio voltage to reach the driver while holding the carrier down. A NPN transistor in place of the resistor makes it variable. I know we put a carrier control into one or another new radio like that...

Don't tell me, let me guess. The owner drove it with a General Lee. There are three 1N4148 diodes and a couple of zener diodes that control the gate voltage on the MOSFETs. They can become collateral damage when MOSFETs fail. If they are damaged and the gate voltage is too high, you'll poof new...

Don't remember seeing a Nightwatch radio that wasn't also a Sound Tracker. The "NW/ST" schematic is in the CB Tricks Cobra section. The Cobra 29 Zoo is pretty populous, and not every version has full info out there. 73

The stress of removing a small electrolytic makes it no longer reliable. We keep the popular value caps handy and just replace any that have to be removed. 73

Age alone takes its toll on aluminum electrolytic capacitors. The liquid chemistry inside that makes them work is held inside by a rubber plug at one end. High temperatures make the rubber rigid, and it shrinks. The seal is broken and that precious liquid chemistry evaporates. Heat speeds this...

Here is a grubby diagram of the Mohawk 10. The HV transformer winding is marked 1000 Volts. Should produce about 2800 Volts from the full-wave voltage doubler circuit. This is at the very optimistic side for the 572B tube. If the filter caps in the high voltage are original, they will cause...

More inductance is just more inductance in this circuit. Shouldn't matter whether its one or two coils that add up to the needed inductance. Seems to me we use between 7/10 and 1 uH for that. An open-core coil you can squeeze or stretch to trim the optimum value works for us. Try 7 or 8 turns...

I would start at the emitter of TR11 and see that the 7.3435 crystal isn't weak. Should see around 1 Volt peak-to-peak RF at TR11 emitter. There are other possible culprits, but they are all downstream from the AM-only mixer TR12 where this signal feeds to. This crystal is in a socket. If you...

Two steps forward, one step back. After running for about a half hour, the blower developed a rattle sound. Didn't matter what caused it. I had bought blowers for this project and have them on hand. The new one is quieter. Came from Amazon. Copped out and skipped making a metal bracket to...

A trimpot is not so different from a volume control. Sooner or later the resistor surface gets contaminated and the control becomes "scratchy". You can hear it in a volume control, but an internal adjustment simply acts erratic or wrong. A drop of cleaner, and a few excursions of the wiper...

The topside is looking a lot more legit. The pi-network tank coil it came with did not appeal to me. I have lots of D&A plated copper tubing. Removing the bogus ham-band coverage and band selector improves reliability in a Phantom or Maverick. And EET'S ALIYEEEV! Got lazy and bypassed...