I want to thank everyone who replied on and off the list. I never thought much about dummy loads before now. Previously I had only used them as a safe place to dump power when repairing a radio or am
Sort of. I dislike the use of the term "regulation" when there is no regulator in the circuit, but that's my personal problem. The type of voltage doubler circuit used determines ripple frequency and
Shipping to a different country is not like shipping to another state. The package will have to clear customs and, depending on the HTS code and destination, duties may have to be paid. UPS, Fedex an
Perhaps, but part of what keeps an RF vacuum tube price high is the amount of skilled labor required to assemble and test it. Even if the value proposition was zero, the incremental manufacturing cos
The anode cooler is welded to the outside of the anode. The ceramic is just an insulator that isolates the anode from the socket and does not much factor into cooling the tube. I have an 8877 in my h
With an external anode tube (and I'll use the 8877 as an example because I have one close at hand), a plate dissipation of 1500W is spread over the anode. Without the cooler, that's still about 12.5
That penultimate sentence should read the drain LEAD is not an active element. Of course the drain is. But the actual drain where all the electrical action happens is on the silicon. The lead is an e
I'm a digital kind of guy. I think the combination of an optical shaft encoder and a microcontroller (PIC, Arduino, whatever) to handle the various control tasks would give you a lot of flexibility w
Speaking in broad generalities, that's all you need to do. PIC processors, as an example, have flash memory that can be used for persistent storage. You turn your relative position indicator into abs
I have a 998 that I use with a G5RV at home, which is basically a temporary QTH until we sell the house. The good stuff is at the lake house. I can tell you that I have smoked the OEM bypass capacito
I know it's not AM, but I have an AL-1500 that I use for RTTY contesting at maximum output. It runs for hours at a time without problems. I believe I've read (maybe in the manual?) that it was rated
Well, if there is SWR on the line, then it is an impedence transformer and the amount of transformation is determined by line length. SWR is, by definition, the same everywhere along a length of loss
I purchased a Chinese 8877 from Henry radio 2 years ago that came with a 1 year (IIRC) guarantee. It was a bit more than the eBay specials that are sold with no guarantee, but was still less than $60
Unless something changed, Harbach Electronics now makes/sells the Dahl transformers. Al AB2ZY Hello all, Where do you look for a new HV plate transformer these days? I understand Peter Dahl is no lon
I think TRIG (pin 2 of the 555) is supposed to be wired to the junction of the 100K resistor and collector of the phototransistor in the opto isolator. The equivalent of a "typo" in a schematic. Al A
I did it on an AL-1500. It came with photocopied, hand-written notes by Tom W8JI. It was simple. I think I may have skipped drilling any holes and mounting the PCB with just two standoffs - I don't r
Larry, I found the notes that accompanied the relay replacement. I can scan and email them if you like. They did jog my memory. Probably what may have scared W8WWV was the low voltage power supply mo
First off, NEC codes end at the outlet. An amp is an "appliance" and would be covered by UL, which is entirely optional. There is nothing that forbids such a practice - an electric range is a good ex
I ran across this and thought it might be of some interest here. It's hosted by Digi-key. I tried it out and it works as well as Visio, with the added advantage of compiling a BOM and the ability to
I don't understand why you would want to use the peak reading function to tune an amplifier. The time delay before decay just makes tuning harder and doesn't really add any value. I also have an LP-1