Search results

Good call! This should also reduce the driver tube's apparent drive power level. This is almost always a good thing. A single driver tube is a good match for 1960s radios that would bust a gut to dead key 3 and swing 11 or 12 Watts. And a tube-type CB final stage wouldn't care so much about the...

This guy has aluminum-nitride TO-220 washers. Just sliding one of these (with a layer of compound) under the part would take up the slack, remove the air gap and be the most labor-effective answer IMHO...

$139 in 1975 inflates to $845 in 2024 minibucks. 73

One problem with substituting a thinner insulating washer is how to close the gap left by the the thinner insulating layer. For a 3-legged transistor it's not a big deal. Those leads are lapped against the foil traces on the edge of the pc board. Desolder, bolt it down and resolder. The audio...

The transformer supplies 13 or more Volts to the tube heaters. The 8950 heater is rated for 13 Volts, not 12.6. Would be no trick to set it up for that tube. Would require cutting a foil trace and adding a wire to the socket of each of three pairs of tubes. Could be the 6.3-Volt TV tubes were...

Hmmm. MN6040 is a Mitsubishi made part. Clone of the Motorola MC145109. Can't remember who made the PLL02A clone of the '109. Nucleonic Products, maybe? The 16-pin little brother to the 18-pin MC145106 used in a million Galaxy/Connex/Superstar/etc radios for decades. 73

The parts-placement diagram in the Thomas book shows the ghostly-gray foil traces. Also the board number, but not quite clearly enough to make out. It's a mirror image of "EPT36001(glob)". It's on the board's edge just forward from the speaker amp chip. It's definitely one or more revisions...

Or a (gasp) counterfeit? 73

Paypal should allow you to send money without signing up as a member. You use a credit card for a one-time transaction. That was the deal last time I checked. Could have changed since. 73

The same little white ceramic component seen there is found on the open market with wire leads. The low-pressure gas inside is an insulator until a threshold voltage is reached and the gas ionizes. Then it becomes a low resistance. They're used in telephone equipment, industrial stuff that can...

Rock on! You found it. Gotta love it when a plan comes together. 73

C48 is a horse of a different color. It handles all the AC current feeding audio power from the audio chip to the audio transformer. That part works hard, and if it has too much resistance inside, it will get hot. And heat is bad juju for electrolytic caps. Makes me wonder if it wasn't a...

Doesn't make much sense. The empty spot appears to be C117. It's connected to the base of TR21. Should be a low-energy point in the circuit. Not sure how enough current can reach this cap to make it bulge. Or is this a different cap than C117? 73

Yeah. The two itty-bitty diodes D52 and D75 alongside the large crystal are in place. They need to go. 73

I used to call the DAK Mark X the King of Disco. All flash and not much inside. One look and people thought it was the ship-to-shore radio from the Queen Mary. A good cabinet, not a lot else. 73

Best of my recollection is that one wire near the relay gets unhooked, the transmit-side wire. Another wire is disconnected from the relay's receive side and gets connected to ground. Next time I'm at work I'll see if we have anything more specific on file. 73

The guy who designs the Skywave amplifiers is real engineer, best I can tell. Name is Brian. First encountered him on usenet 25 or so years back. He has a YouTube channel. Still puzzles me that he won't use a peak-reading wattmeter. His designs are usually well thought-out. And yeah, the plastic...

A custom-made LCD will have complete symbols. Only takes one data bit from the computer per each of those. The dot-matrix suggestion would allow you to mimic the dedicated symbols on a factory LCD. No good way to fabricate a copy of a custom LCD display. 73

Must be from outside the USA. That brand name is sold in europe and ANZAC. It's not listed at CB Tricks nor in the Howard Sams master index. A foreigner or an orphan. 73

That power supply is still about double what the radio needs. No way it will ever come close to breaking a sweat. 73