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Yep, those are called "K-Tran" IF/RF transformers. They tune with a cup core on the outside of the winding, rather than with a hollow core and a slug on the inside. It was a high-performance part back in the day. The cup core was also a magnetic shield. You could crowd them closer together...

The HV filter caps all look original. Can't make out date codes printed on any of them, but I'm pretty sure that brand "Industrial" has been gone for 40-plus years. 73

Cans? As in slug-tuned IF/RF transformers? Yeah, most of them. T1 doesn't. It relies on C11 to tune it to resonance. The rest of them have at least on internal disc cap. 73

How many of the 10 or 12 electrolytic capacitors have been replaced? If any of them are original, this is trouble in the making even if all of them still work today. Good chance at least one of them is contributing to reduced performance. 73

Whupsie. Much bigger. My bad. Forgot how large that model's transmit power is. 73

Consider that a measurement in steps of 0.01 Volt has an uncertainty more or less equal to this lower limit. A difference that small just isn't significant. The rule for matching is the closer the better. We test a batch of 20 or 50 and mark the last digits on the rear. They get paired up by the...

Was also used as the power/speaker socket for 1970s car stereos. Can't remember what brand. 73

The problem is the amplifier is meant for a single-final radio. You're hitting it with about double what it's meant for. Any radio that has to be turned down below a one-Watt carrier is just too big. Simple, cheap fix is to push in the "AM" button. Should drop the gain enough to accomodate a...

If the mismatch increases with power level increase, two possibilities emerge. Either the amplifier's signal purity suffers as the power increases and it's adding a second frequency not in the band you're tuned for. Or the core of an inductor is saturating past 150 Watts, reducing its...

A quarter-Watt 10 ohm won't get hot until there is a breakdown. 73

This was a classic "swiss cheese" failure. Multiple boo-boos had to all line up with each other just right. Turns out a redundant system would have kicked in and prevented loss of rudder authority and propulsion if it had been configured properly. That one bad connection should have had a backup...

If it changes frequency when you turn the channel selector and gives you the right channel, it can't be bad. 73

Or if the crystals in the sideband filter have drifted or failed. Or both? 73

Works fine for receive. Don't know the math to predict the transmit wattage it might tolerate. Besides, an air variable used outdoors will have to be protected from rain and condensation. Got an enormous air variable I need to unload that has 5/8-inch spacing. Never did find a practical use for...

There are two other coils alongside that one, L21 and L22. They should affect sideband modes only. Rock the slug in each one, just enough to return it to the original position while watching the radio's frequency. If either of those causes a change while in AM mode, there is a switching fault in...

Pretty sure L20 is the adjustment to make AM line up with the sideband modes. 73

Shoot me your PayPal addy and I'll buy them that way if you like. Or send a money request to PP member nomadradio@yahoo.com. 73, Chris

Probably 47pf. We use 22pf, but clearly it's not all that critical. The big deal is to remove C163. 73

Roger that. The 5221 is a Read-Only-Memory that stores the binary codes that feed into the PLL section. And it's a dead duck without that negative bias voltage. Should survive that side of the power supply shutting down. Just won't work without it. Oh, and it's not an "E" PROM, just a ROM. No...

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