How are you going to use an SB-200 as a "tube checker"? The 572B tubes used in the SB-200 are 4-pin "medium" and the 4-400A and 3-500Z tubes use a 5-pin "large"! Then there is problem of the filame
I need a couple of 4CX250B tubes to have on hand as spares for my single 4CX250B 432 MHz amplifier. I thought I had a new Amprex tube. Unfortunately, this brand new tube has an open heater! I do h
No! The 30S-1 recommends a length of 20.5 feet but the specification for the 30L-1 was changed to basically any length of cable with 48 inches being the generally accepted length of RG58/U because th
There was a later Service Letter, not a true Service Bulletin put out rescinding this requirement. Somewhere, I think I have a copy of the Service Letter. I will try to find it. I don't know if ther
If you have a color printer you can print one yourself on various Avery label stock. Spray clear Krylon over the label to weatherproof it. Glen, K9STH Website: http://k9sth.com ___________________
The r.f. choke to ground is to prevent the B+ from flowing on the antenna if the plate coupling capacitor shorts. In normal operation, theoretically no current will flow. When the coupling capacitor
It may be r.f. getting back into his exciter from the fact that more power is now being used. Glen, K9STH Website: http://k9sth.com Hello Guys, Just sent a little 2m gi7b amplifier to a ham in idah
The electrolytic capacitors in my Henry / Tempo 2001 lasted for 38-years and then 3 of them "went" at the same time. Glen, K9STH Website: http://k9sth.com ________________________________ From: Edd
It really depends on how much the equipment is used as to how long the electrolytic capacitors last. The more that the equipment is used the capacitors last longer. Sitting in an unused state for l
Fortunately, I had replacement capacitors in stock. Got the amplifier back on the air in about an hour. They didn't explode, just let out a LOT of smoke. Glen, K9STH Website: http://k9sth.com ____
When I was in high school, the physics teacher decided to have a one-semester "electronics" class. There were parts from all sorts of discarded television sets around. A couple of the less bright s
I had a distributor who decided to start tuning all of the two-way radios that he sold instead of having my company tune them for the desired frequency. He set up a test bench and tried some of the
How many 01 tubes does your amplifier use! 89 years ago! :>) As for more output: Theoretically, using a larger diameter cable should reduce the losses in the cable which, in turn, should produce m
I have found an easier way of soldering those pins. What I do is to place the pin in a hole drilled in a piece of wood that just holds the pin upright. Next, I tin the center conductor of the coax.
Check the germanium diode that provides the voltage for the "forward" or, in this case, the power output, indication. There are 2-diodes, 1 for forward and 1 for reverse (SWR position). It sounds l
With a slight reduction in readings. Using a Schottky diode would be a better approach. I would replace both diodes in the SWR bridge with like diodes just to keep some semblance of accuracy. Gle
I only ran my new GI-7bT tubes for a few hours on just the heater before applying high voltage. They are working fine in my home-brew 160-meter amplifier. Glen, K9STH Website: http://k9sth.com ___
Collins rescinded the need for the 20.5-foot input cable for the 30L-1. It is still recommended for the 30S-1. The "normal" 48-inch RG58/U with RCA connectors on each end replaced the 20.5-foot cab
Having spent 10-years with TXU, the electric company for almost half the State of Texas: The ambient line voltage for most major electric companies has been 125-volts +/- 2-volts for decades. Becaus
Before purchasing any transformer oil, go by your local electric company service center. The electric companies use transformer oil by the 55-gallon drum. Offer to buy a gallon. The vast majority