** Thanks for the input, Dave, however, Eric's stonewalling my questions about possibly knowing the other person who uses the term "voodoo parasitics" suggests that he here on a mission. [note -- the
Ceramic insulation, Ag-plated, 7-position, 3-pole, DC stepper-drive, c. 3.5" dia., c. 12kV between open contacts, $40, moneyback guarantee. - R. L. Measures, a.k.a. Rich..., 805.386.3734, AG6K, www.v
** good point, however, I have not yet found an arc-mark on the grid cage of a 3-500Z with a bent filament helix that shorted against the grid cage. Nor have I found an anode-grid withstanding poten
** I don't know, but if enough power is absorbed by the choke, a choke fire seems likely. ** When in doubt, punt or remove turns. - R. L. Measures, a.k.a. Rich..., 805.386.3734, AG6K, www.vcnet.com/
27MHz is within 4% of the 28MHz band. That's seemingly because less than a few of the guys who wrote about amplifiers actually built 'em. I too read the handbooks, and it took the experience of an 8
wow. 50k amperes is like a smallish lightning stroke. About as big as your thumb? For years, accepted aeronautical engineering theory said a bumble bee can't fly. The perplexing thing about bent fil
Tubes are immune to Earth's magnetic field ? Good question. What is the fusing current of #28 Cu ? It must be at least 15A, and yet the 3-500Z cathode/filament is theoretically not capable of such a
The SB-221 was the first Heath amp with a CB filter. The HL-2200 was the second. A CB radio technician worth his salt can convert a SB-221 to 11m in under 15 minutes. Not that I have seen. However,
SB-220 The 2200 has a CB filter, a different cabinet design and it lacks the puke-green paint. - R. L. Measures, a.k.a. Rich..., 805.386.3734, AG6K, www.vcnet.com/measures. end
Negative grid current during standby/Rx usually means a grid-filament short when the filament is hot. However, the short may not be present when the filament is cold. Such shorts are the result of a
The anode-cathode feedback C in a g-g 8877/3CX1500A7 is 0.1pF. How much is it in a C7 ? curiosity. - R. L. Measures, a.k.a. Rich..., 805.386.3734, AG6K, www.vcnet.com/measures. end
If the thoriated tungsten filament was not at a temperature of 1820?K, probably nothing would bend during an event. cheers, Dom - R. L. Measures, a.k.a. Rich..., 805.386.3734, AG6K, www.vcnet.com/me
** I need some measurements during the big-bang that preceeded a grid-fil short. - R. L. Measures, a.k.a. Rich..., 805.386.3734, AG6K, www.vcnet.com/measures. end
In their specs, higher resistance ww 100w resistors are voltage-limited, so one should not assume that a 200k-ohm, "100w" resistor will be able to withstand 4472V, or that a 100k-ohm "100w" resistor
Many of the denizens on AMPS find discussions of parasites odious. The only semi-plausible explanation to bent filaments is that some Hams are using their 3-500Z amplifiers in aerobatic airplanes -
If electric current can move heavy Cu welding cables a few inches, the effect does not seem trivial. New Eimac 3-500Zs have a grid withstanding potential of 8 - 9 kV. The amount of bulge from the be