Search results

If all you care about is 11 meters, use the "A" slug. Covers 25 to 60 MHz. Tends to cost half as much as the "H" version for the same wattage. 73

Sounds like the SMT resistor poof. The 7805 will show around a Volt on the input pin. Thought I had a pic of the fix on my ImageShack account, but I can't find it. Those folks have developed some twitchiness in their database. The gist of it is pretty simple. Find the pin that feeds main power...

I have a Tenma brand 40-Amp supply that looks just like it, but with gray paint. I'll have a look inside and see if there's a blue and yellow wire like this one has. Even if it came from the same factory as yours, no guarantee they used the same wire colors. 73

The Bird's claim to fame dates back to the dark ages when the only way to tune the antenna on a police car or fire engine was with a wattmeter. It was the universal standard in business-radio installation/maintenance when I was wet behind the ears. The Bird's popularity was with its ruggedness...

Holy crapola! Doesn't look any older than me. Naturally people want to know what happened to him. Tracking down a local obituary would be one thing. Getting it translated would be necessary for me. RIP, Jim. 73

I do hope this is not a duplicate. Just don't have the patience to scroll back up 163 pages of posts to see. Seems appropo. 73

I discovered the 459 was good for just one thing. People pay stupid money for them on fleabay. Years ago I cleared out parts radios that never had a part removed and models I won't touch any more. That was one of them. The market may have changed, but it was worth a lot more in someone else's...

Hmm. I've been thinking open circuit between the relay and tube cathodes. Clearly not so. Maybe what's causing the mismatch is a leaky part with one side grounded? If it's not a problem in series with the drive signal, maybe it's a fault in parallel with the signal input? 73

Not the 459. That's the computerized nightmare radio. 73

That's more than I could pull out of my hat on short notice. 73

The Uniden PC board number is PC385. The Uniden Washington is the same inside, the Tram D300, RatShack TRC490, and others that just don't come to mind right now. 73

That's odd. As a rule, adding that choke in line with the varactor reduces the feedback through the crystal causing it to stop running with the clarifier turned to the right. Adding capacitors can do the same thing for the same reason. But I'm not used to seeing this fault with the crystal...

Someone requested the truth chart for the Cobra 142GTL and I neglected to make a note of where that was posted. Can't find that thread right now. I scanned it, and it occurred to me that a little explanation might be helpful. The column marked Divider Input is the frequency you'll see at pin...

If you connect the 11.1125 crystal directly to the two foil pads on the main pc board where it was originally installed, the clarifier glitch should go away. The added capacitors are causing the dropout symptom. 73

Is there a small RF choke added in line with the varactor diode? That trick works with similar radios that have three trimmer coils, one for each mode. This radio has a trimmer cap for USB, and a coil each for AM and LSB. That choke has to be installed differently for this radio, or better yet...

Ah, is the 8719 chip getting the full 8 Volts DC? If not, this kind of twitch can result. 73

Any chance that the slug in L13 is near the rim of the hole in the can? The VCO frequency is supposed to be above the 33.33 MHz third harmonic of the 11.1125 crystal. The difference between the VCO frequency and the crystal harmonic is what gets fed into pin 17 of the 8719 PLL chip. Trouble is...

Most consistend aggravation with those was the solder connections between top side foil and bottom side foil. They used tiny posts in a hole that completed that top-to-bottom circuit. For whatever reason the solder would develop fatigue cracks on those pads and have to be resoldered from time to...

It's a finely-balanced design. The driver is a 500-Volt tube with 1200 Volts on the plate. By rights it should go poof the first time it's keyed. Had a memorable conversation with an "engineer" at Wawasee Electronics many decades ago. Asked him how they get away with that. He explained that...

The series filament connection lets you use wire half as thick on the cathode choke. Also shrinks the wire size needed to wind the filament secondary on the power transformer. Just be sure to put a fan of some sort just below the tube sockets. Doesn't have to be big, only needs a breeze not a...