? Briefly: The filament transformer is unfused. It has an 11v winding and an 80v winding. If either secondary winding is shorted, the transformer will literally melt down. The 80v winding powers a +
? A photograph of a grid/filament shorted 3-500Z appears on p. 15 of the September, 1990 *QST*. The title of the article is "Parasitics Revisited". ? The 922 was designed for the TS-820S transciever
Tom ? Why?. My TL-922 produces no audible hum-modulation on SSB. I hear no hum-modulation from other 922s. Henry has been using seriesed filaments for years. ? Perhaps -- if the filaments are not of
? Even so, driving RF will be across the input contacts before they close. This will result in arcing the input contacts during closure. ? If input contact arcing takes place, transients are fed to
? Readers can check Will's archive to see what Mr. Rauch stated during the grate parasitics debate. - to find the place, search for "5 Dec 1996" or "161MHz". This is the part of the debate where Mr.
? To assist in identifying what kind of problem caused an event, measure the resistance of the parasitic suppressor resistor(s). Such resistors are virtually shorted by roughly 0.002 ohms of copper
? As I recall, during the grate parasitics debate, Mr Rauch disclosed that had measured self-resonances in Tune-caps that were in the 100 to 200 MHz range. Rich... R. L. Measures, 805-386-3734, AG6K
? What is the likely Z of a high-Q series-resonant circuit on frequencies above and below the frequency of resonance? As I recall, you measured an AL80 Tune-C series-resonance at c. 180MHz, and the
? I agree that not much VHF energy can make it to the tube. The VHF energy comes not from the transceiver. It comes from damped-wave ringing in the anode-resonant circuit. This (VHF) ringing occurs
? Switching to the opposite sideband was also popular. Ten minutes later, the lock-to-talk guy unkeys and wonders what happened. . ? Jon: A friend drops by for a visit. He makes a 10 or so minute lo
? Very much like a hammer (the transient) striking a bell (the resonant circuit). This is how spark transmitters worked in days of yore. Rich... R. L. Measures, 805-386-3734, AG6K, www.vcnet.com/mea
? A spark is reliable producer of wide-band feculence. ? hotswitching causes a spark. ? The spark is connected to a wire that connects to the input of the tube. ? When I was on 1296MHz, I could hear
? In order to develop a high potential, high current flow is essential. Series-resonance causes high current-flow. Parallel-resonance does not. . At the frequency of series-resonance, virtually no p
? One of the seemingly better articles on the treatment of vhf parasitics was written by a commercial amplifier engineer who worked for the General Electric Co. ("Parasites and Instability in Radio
? "I'm trying to think but nuthin' happens". . .Curly ? Sparking contacts don't create transients? ? we are not talking about the bias contacts. We are talking hotswitching the RF input contacts whe
? Would you expect a change in input potential to cause a change in anode current? Rich... R. L. Measures, 805-386-3734, AG6K, www.vcnet.com/measures -- FAQ on WWW: http://www.contesting.com/ampfaq.
....... ? Rich knows that all power grid tubes have finite emissive capabilities. He also knows that when over-driven, a TL-922 can not produce much more than 1800w-pep due the emissive limit of a 3
? amen, Peter Rich... R. L. Measures, 805-386-3734, AG6K, www.vcnet.com/measures -- FAQ on WWW: http://www.contesting.com/ampfaq.html Submissions: amps@contesting.com Administrative requests: amps-R
? Impossible? see page 33 in the Oct., 1990 *QST*. I observed no "poor wiring" in this TL-922. Rich... R. L. Measures, 805-386-3734, AG6K, www.vcnet.com/measures -- FAQ on WWW: http://www.contesting
? agreed ? which is probably why many Anglophones consider Wm. Shakespeare to be one of the architects of modern English. - interesting discourse, Jim Rich... R. L. Measures, 805-386-3734, AG6K, www