The rated closure time for the Kilovac? HC-1 is 6mS. I measured c. 5.9mS without a speedup circuit. If the actual closure speed was 2.3mS, one would think that Kilovac would spec the HC-1 at 2.5mS in
** What about those who do not use PTT -- i.e., folks like yours truly who use VOX? In this case, the (+DC-V on Tx) signal switches between +12V or so on Tx and 0V on Rx. This signal is ideal for co
? Good points, Ian. The solution is to allow the transceiver to control the EBS with its +DC-V on Tx signal. This gives the RF relay contacts in the amplifier at least a 5mS headstart so they can be
? if the Millen HV connector is still made from molded phenolic, there could be a problem since phenolic resin absorbs water vapour from the air, and thereby becomes conductive.
False logic? I don't believe it is good design practice to ever allow an on-line high power amplifier to look into an open circuit, even if no drive is present. To do so is to invite instability. The
Jim, You're right in principle, of course. The problem is that a well-designed amplifier relay circuit shouldn't depend on what transceiver is used. The amplifier itself should be immune to hot-switc
I agree with everything you said. The problem with some radios is they start sending' RF down the line at the same time they are giving the relays the energize signal. I have built some big amplifier
Its actually very simple Jim. Don't send RF until the amplifier is ready. Not doing so, makes the relays hot switch. It matters not which one is energized before RF is sent. As long as they both are
Oh... And if the relays (either of them) are NOT ready for RF, you get hot switching. As well... If they are DE-energised before RF stops flowing from the exciter, you also have hot switching. Thanks
Not necessarily! Really there no need for a faster input relay or a faster output relay. That is all false logic. I matters NOT which relay closes or opens first... AS LONG AS the RF is not sent from
Bob, Years ago, I bought a lifetime supply of RJ1As for my own projects, and have tested roughly two dozen on my homebrew relay tester. The RJ1As typically close in about 2msec, with the fastest clos
I must be old school. The input relays need to be slower than the output relay. Seems to me that a RJ-1 takes 8ms to close and stop bouncing around. I have always used a P&B miniature open frame DPDT
Those relays that Rich (and I ) used are mostly unavailable. I used to buy them 100s at a time. No more of them can be had. Most of what you find on eBay are seconds and most don't work. Or they are
G'day Vic. The Matsushita/Panasonic relay that Rich Measures used in his QSK circuit, published atsomis.org, is still available on Ebay. I bought 10 of them a couple of years ago Otherwise, Jim, W7R
Friends, I was asked to look at and do appropriate repairs /upgrades for a Heathkit SB 221. Photo album of As-found 221, and a W8JI photo, also, are at: http://www.facebook.com/media/set/?set=a.23226
Its also depleting the ozone and wasting carbon credits. Since we are already in looney tune land with this thread it might as well as encompass other loonies. Carl __________________________________
one may be able to have the suppressor coaxed into toasting morning toast. the Ni-Cr ribbon in his uppressor began to glow like an electrical heater element a very I'm not going to be baited into thi