ORIGINAL MESSAGE: REPLY: You don't say what kind of scope you have, but assuming you have a triggered-sweep type, set the scope for normal triggering (not auto), DC triggering and about 5 mS per divi
ORIGINAL MESSAGE: REPLY: When reading the characteristic curves chart, it doesn't matter whether the tube is operated in GG or 'normal'. Just select the plate voltage and the desired idling current a
ORIGINAL MESSAGE: REPLY: Does it do it on a dummy load? You could have a loose connection in the antenna or coax that momentarily drives up the SWR. If you have several antennas, does it do it on all
ORIGINAL MESSAGE: REPLY: I would perform an experiment. Set up the amp out in the open and monitor the exhaust temperature with a simple oven thermometer. Run it at the manufacturer's rated 100% key-
ORIGINAL MESSAGE: <snip> REPLY: The value of the coupling cap is probably the least critical of any capacitor in the entire amplifier. Its current and voltage rating must be equal to the task, but th
ORIGINAL MESSAGE: REPLY: That just means you need a better socket. :-) 73, Bill W6WRT _______________________________________________ Amps mailing list Amps@contesting.com http://lists.contesting.com
ORIGINAL MESSAGE: REPLY: That's a very good question Robert, but I think the best way is to pack them so well it doesn't matter. I'm not trying to be a smarty here, it's just that they are so delicat
ORIGINAL MESSAGE: REPLY: Every amplifier I have ever owned has exhibited current drift similar to what you have seen. When you apply power, literally everything in there starts heating up and heat ca
ORIGINAL MESSAGE: REPLY: That is true, but vacuum variables are most easily damaged by impact, not crushing. I had one which was sitting on its end on a table. While working on something, I just bare
ORIGINAL MESSAGE: REPLY: Do you mean a connection to a turn on the tank coil? If so, I use a piece of thin brass strap, 1/4 inch wide. I form it around a wire or drill bit which is just a tiny bit sm
ORIGINAL MESSAGE: REPLY: Before I can answer the question I need to know two things: Is it a dual trace scope, and is it a triggered-sweep or 'synchronized' sweep scope? 73, Bill W6WRT ______________
ORIGINAL MESSAGE: REPLY: Ok, the best way to observe relay closure is to temporarily wire a DC source to each relay's armature (the movable wiper) and connect the output of each relay to one channel
ORIGINAL MESSAGE: REPLY: Very clever! As a long time scope junkie I would have never thought of that in a million years, but I will keep it in mind for the future. 73, Bill W6WRT ____________________
Looking for some ideas on how to best design an amp. In September, Flex Radio is going to offer a Software Defined Radio, model Flex-1500, for just under $600. It will be a QRP version with only five
ORIGINAL MESSAGE: REPLY: This is an ancient design and was pretty much abandoned years ago for good reason. Take a look at handbooks from the '30s and '40s and you will find it there. There are two m
You have done a good job of evaluating the situation, Kevin. I can add a few comments: I purchased one of the first AL-1200's in the mid-1990s and used it for RTTY contesting. I ran it at close to 15
ORIGINAL MESSAGE: REPLY: Sweep tubes are not intended to run with any color on the plates. If you need more output, bet a bigger tube. I did TV repair for nearly 20 years back in the tube era. A glow
ORIGINAL MESSAGE: REPLY: Ok, I didn't realize they were that old. Mine was purchased in the mid-90s. 73, Bill W6WRT _______________________________________________ Amps mailing list Amps@contesting.c
ORIGINAL MESSAGE: REPLY: My feeling is that if it were used mostly in S&P mode or in occasional CQ mode it would be ok. I would not recommend a long string of unanswered CQs on 80 or 160 meters where
ORIGINAL MESSAGE: REPLY: That was enough years ago that I can't honestly remember, but I was probably using a Kenwood SWR/Power meter at the time. In any event, since I know power meters are notoriou