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If one of the three input capacitors is shorted, it is likely to show that short at DC on an OHM meter. It is also likely that lifting them out of the circuit will restore some output if they are defective, although it will be out of tune. I wouldn't drive it hard or operate it long in this...

That's unique. Notice how the roller inductor seems to allow this tuner to achieve a match in a simple "L" configuration, rather than a Pi with two variable caps.

Since the tubes are wired as grounded grid triodes, is there any reason we are not biasing them as such, through the cathode? It seems like lifting RFC 1 from ground and inserting a zener or a string of silicone diodes bypassed with a cap, would be the way to go here. You can precisely dial in...

Now show it working stable on sideband, with the cover closed? Without a drop of RF shielding and 700 watts a fraction of an inch from all of the low power circuitry, this radio should be quite the oscillator, without a carrier swamping out the oscillations. Where is the decoupling for the...

This option allows you to purchase an amplifier with real linear rated RF transistors. Something completely absent in today's "all in one radios".

I learned something new here. I never knew they made a metal plate to prevent both circuit breakers from being on simultaneously. Thanks for the information.

That is the method I use to use, with a pair of low profile flathead screws to hold the transistors in place. Sometimes it required extra washers under the PC board mounting screws, in order to provide clearance under the board for the transistor mounting screws. Just make sure the relays and...

Another option is to just use a decent relay to handle the switching from B+, to modulated DC. Had to do that on D201 that got a voltage increase to run a pair of 6146 tubes.

You can use any tap as a primary as long as you do not apply more than the rated voltage or, draw more current than that winding is rated for.

The 3 input caps I'm talking about are all in parallel with each other and connected from the copper input coil, to ground.

It's been a long time since I've used one. Back then the goal used to be a one farad capacitor. Today that value is easy to achieve and I've seen many that are two farads. They typically have a maximum voltage of 15 or 16 volts and match a stock electrical voltage system well. The goal is to...

Unless you are using the amplifier on sideband, the answer is no. The capacitor is only beneficial for intermittent loads. The sustained load of a carrier on AM will defeat the purpose.

Yes you need to disconnect the capacitor to test it for a short because, it will read a short through the combiner and secondary winding of the output transformers. If that part checks out along with the three capacitors across the input coil, you should consider running a low-power test where...

Another option is to take the output of the one amp regulator and feed it into the base of a much larger NPN transistor. Tie the collector of that transistor to the unregulated voltage and the emitter will supply much higher current at regulated voltage. The transistor will cause a 0.6 volt drop...

I would suspect those three dipped silver Mica capacitors across the input coil. You might want to remove them and test them. Another way to confirm this as a possibility would be to drive the amplifier with just the radio and see what the input SWR is. Don't key it for long, in the event I'm...

Getting 64 transistors to all run within a 2-watt balance of each other and not heat this resistor, is a difficult task. I've seen a different builder use 100,000 ohm resistors rather than 100 ohm resistors. When I asked him why, he said they don't smoke...

The 6LB6 is close to an 8950 however, it has 300 milliamps less peak cathode current and slightly less output capability as a result.

Forgive me for having a difference of opinion here however, in my mind it's not the extra power the 5th tube makes. It's removing 20% of the load off of the other four finals, that are already being pushed and essentially still receiving the same amount of drive power that was feeding five...

Imagine an 11 meter rig running a 6L6 audio tube, modulating a 6L6 RF tube? 50 years later, the Tram D201 is still hard to beat.

"the "techs" here are cb guys that only work on easy shit. None can do more than peak and tunes." Not for nothing however, that is a classic example of being a condescending jerk. It was as though you didn't even read the responses you received, before making that post. In any event, relax, we...