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Hi Don, Yeah, I noticed the asymmetry in current, too.? Thanks to your markup, it's clear that the current that goes through the rectifiers is about 0.4 A higher on one side than the other.? The

Halden, I admire your work on this project, but for now I am bypassing the design details of the new circuit. Img ..35 seems to show a very dominant resistive load [heaters and filaments] and a very

Here’s an update on the circuit I mentioned earlier for avoiding the occasional “thunggg” turn-on sound which is due to remanence-induced current surge. This circuit might reduce stress on the

I used a fixed value resistor, 2.5 megohm as I recall this eliminates the need for the dual pot. Easy to play with the resistor value to get the desired delay. Just my two bits. Mike W0FD

The original modification for break in cw will accomplish this but since the dual pot is hard to implement, requires two pots to duplicate. Still, it can be done. Transmitter still is in MOX but now

That's a much better idea! Bob W4JFA [email protected]> wrote:

There was a factory mod that was issued to make it a semi break in cw rig using the vox circuit. Seems like it is just a wire from the function switch to a high value resistor connected to the vox

Maybe you can build a transistor, FET, or opto-coupler switching circuit inside while leaving the original switch intact. It can be built on a very small perf board. Just a thought. Bob W4JFA

Does anyone know of a way to key the HT 37 on CW without having to switch the Operation switch from MOX to Standby at the end of a transmission?? I don't necessarily mind doing that but I don't want

I purchased a used HA1 keyer for a project I’m probably never going to complete. The keyer cosmetics are about a 7 with minor surface scratches on top. The front panel is clear. I have not tested it

Jim I did change the capacitors, and I did replace all the valves/tubes taken from my second radio which were in a working condition ( I don’t have access to a valve/tube tester).To be honest I

After testing every tube but the finals on a non-working HT-44 (everything lights, no bias current pulled), I found both 6DQ5's tested bad.? One had an HK short and the other a short elsewhere if I

Hi John and gang, True, it is a bargain and the best resource of old tube radio reviews and articles out there! I started my subscription around 1996, and was able to purchase the earlier issues

Hi Don and gang, Yes , ER is the finest tube radio magazine in existence! If anyone here is not familiar with Electric Radio Magazine, I suggest you check out their website and subscribe! Since 1989

LyntonBy "original unmolested condition", do you mean to say that all of the original capacitors are still in place?? A leaky coupling capacitor is capable of changing the grid bias on the output

In the S-40 which has a similar audio output but a permanentf6 magnet speaker, the field coil is replaced with a 1500 ohm resistor. There is no spec given for the S-20 transformer in the handbook I

Hello everyone. I have two Hallicrafters S20’s. One has had the audio modified with a large choke (value??) and an output transformer. It produces audio but not very well! The second has the

Thanks for the tips, Rick! 73, Jeff

Thanks, Ken. I'll take 'em. email sent. Jeff

Hi Jeff, $8 each is a pretty good price! I have also bought several 6DQ5's on eBay and the prices are usually no more than $8-10 each some with shipping included.? So far, I've never gotten a bad