I've noticed the same here with an AL-80B: On 240V, the filament voltage runs >5.5V on a 3-500Z (nominally a 5V tube). I spoke with Ameritron on the phone about the issue and their tech told me that
From the Burle site: http://www.burle.com/cgi/byteserver.pl/pdf/tp117.pdf For thoriated tungsten filaments, a 3% increase in voltage results in a 50% decrease in tube life! Check the voltage at the t
G'day Rob It is not any "camp" that makes the claim of shortened emissive life due to high filament voltage. It is Eimac, in its "Care And Feeding" book. For every 3% increased in filament voltage, t
Don't forget, that line voltages can vary over quite a wide range and there are taps on many transformers to adjust for the proper output voltage. Line voltage can easily vary up to around 10%. I don
Hello to All: I feel that one can use the available literature that Eimac published decades ago on this topic. If you go to their web site, they currently list an article on exactly this topic. To cu
Just after I got married I bought two 75 Watt long life 120 Volt "Krypton" lamps for my new front porch lamp as it was a pain to change. (at $5 each) The first lasted 1/2 an hour, thinking it was a
Hi Alek, Thanks for the response. Personally, I agree with you that it is better to keep the filament voltages in check for a number of reasons. However, here's a pointer to a post (from this list) t
One of the times we were losing incandescent lights I measured the voltage and although I don't remember the exact voltage it was high, so I called the power company. I told the power company enginee
Very true Roger. That is a real problem and it makes it hard to make sure you don't go too far the other way. I do my calcs when the line votage is high and set the filament volts 2-3% higher than no
I don't know that you can say that commercial amps are always designed for higher filament voltages. They are designed to handle a certain minimum line voltage but many areas regularly exceed that a
I think it gets back to line voltage regulation. I say that as I'm heavily involved with the old boat anchors and most of those guys will go to extremes to make sure line voltages are down to what th
I re-wired an amplifier heater circuit to an external current-limited stabilised dc supply. We had to fit larger heatsinks and more fans to keep the supply cool and arrange for this to be switched wi
Data is needed to assess the effect of relatively short duration power cycles on filament life. We can read all the conjecture about monitoring rated filament voltage in an effort to extent filament
That may be true but it is hard to come up with any argument to say that it is not beneficial to run the filament at the nominal voltage, rather than some higher value chosen by an amplifier manufact
For some strange reason my voltage has been holding steady at 118-120 for almost 2 years now. Before that it was 124-128. Even so I still use bucking transformers on vintage gear and run at around 11
For several reasons I take anything from that source with a huge grain of salt. There also appear to be several definititions of ICAS with the first going back to the Class C AM days. Without a runni
And in "the old days" we used to try almost any thing to get the voltage up as much as we could. <:-)) We were without power for two weeks back in 74? We were also without power lines for about the s
Carl, I don't think I ever saw you and Tom agree<:-)) Those were back in the days where we pushed to get every watt we could, even knowing a watt or two made no difference at all I always look for CC
I've NEVER had an engine problem DUE to a long run-up. I suspect the pilot of a Beech Duke that took off from Huntsville last week should have done a longer run-up. Don WA4NPL ______________________
I would not even think of flying a helicopter until it warmed up the prescribed time according to the operator handbook - which is virtually at close to full power for a few minutes. I want it to fa