> Date: Mon, 10 Jan 2011 14:25:26 -0500 > From: [email protected] > To: [email protected] > CC: [email protected] > Subject: Re: Topband: Russian Vacuum Variables on EBAY > > Bought two 1200 pf 4 kV for use on big 160 antennas out at N4AF, from > QRO-stuff. No problems and have done the job out in remote box for > seven or eight years now. Very stable. Quite large, drive shaft is > NOT 1/4, 12mm or almost 1/2. Most likely have to fabricate a knob or > reducer. > > Those big things are the final answer, absent direct lightning > strikes, for going the distance QRO. Prices for Jennings brand new > retail are simply awful new, but on eBay the Russian listings are > affordable. This is most like what we bought: > > http://cgi.ebay.com/Vacuum-Variable-Capacitor-10-1200-pF-4kV-New-Box-/200563805228?pt=LH_DefaultDomain_0&hash=item2eb288cc2c#ht_2455wt_1139 > > 73, Guy. > ************************************************************ > On Sun, Jan 9, 2011 at 9:00 PM, Robert Harmon <[email protected]> wrote: > > > > I see some good prices on new Russian vacuum variables on EBAY. Thinking > > about getting several > > for a vertical tuning unit I am planning. Anyone bought vac vars from the > > Russian EBAY vendors, > > good results ? > > > > tnx es 73, > > Bob > > K6UJ ***************************************************************** I've just looked at this auction listing, as well as visiting: http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=260712022418&ssPageName=STRK:MEWAX:IT#ht_2850wt_302 which is now closed. The prices shown, plus shipping, are just a bit north and south of $200 for these glass-encased capacitors. On my desk is a Jennings CMV1-650-0005 that I cannot distinguish from new, and it arrived here last week for $195, plus a nominal amount for shipping from Marietta, GA, USA. Transit time via FedEx was 48 hours. It is ceramic, less fragile than glass, offering 8-650 pF @ 5kV. and with 10 turns' rotation required for its min.-to-max. capacitance variation. The 0.5-inch diameter shaft came with a reducer to 0.25-inch diameter, mounted by the seller. Fitting a 10-turn dial will be easy. This gem will be set to about 255pF and then installed at the base of my 0.37 wavelength (85'up + 85' out) inverted L antenna where, aided by 44 in-ground radials with an aggregate length of just under a mile, it will replace a large "bread-slicer" capacitor and restore my 1.1:1 SWR reading. I feel quite safe that with such a generous breakdown voltage rating I shall have no problems with my almost-always output power of five Watts, but I must give a bit of thought to better protection from lightning damage. This capacitor's seller is the well-known and long-established, MaxGain Systems, whose principal I deem to be a worthy and reputable individual. He knows much more about vacuum variable capacitors than I can ever hope to learn, and, in my estimation, he has the integrity to willingly settle fairly any problem that might arise from a business dealing with his company. Over the Christmas holiday I read the The Economist of 11 December 2010, pages 29-32, "Briefing: The State of Russia", which I highly recommend, and from which I now believe a likely consequence of my recent purchase to be my not having dealt in stolen goods; nor did I worsen the US' balance of payments deficit by adding to this country's substantial trade imbalance. 73 (or perhaps QRP-speak 72), Charles, W2SH _______________________________________________ UR RST IS ... ... ..9 QSB QSB - hw? BK
