Agreed. With a K3 you don't need any special sequencing -- just replace the relay with a reed relay for input and a vacuum relay for output (or two vacuum relays). It is much more pleasant even if you don't use QSK or VOX.
Vic 4X6GP/K2VCO > On May 31, 2015, at 7:21 AM, Guy Olinger K2AV <[email protected]> wrote: > > Expecting a transceiver to somehow neutralize all amp obsolescence is > putting the burden where it doesn't belong. And it really can't come > close to doing the entire job. > > Existing mod kits from Harbach, W7RY, etc, can convert many older amps > internally (all the way back to SB200 SB220) to *excellent* modern > status, QSK, modern interface voltages and behavior, good for years of > slick operating to come. Array Solutions has an excellent external QSK > device, for those who don't want to tackle an internal mod. > > You didn't say which specific amp with slow frame relays. Many (most?) > of these were designed back when the expectation was something like a > footswitch or a toggle switch would be used to place the shack in > transmit mode. > > I own an FT1000MP. On CW (only) it has a first in first out bucket > brigade delay (menu 7-4 keyer break-in time) which allows it to apply > T/R assert to the amp and allow continuously delayed CW up to 30 ms to > be transmitted from the MP. With the clunkier amps actually needing > the max 30 ms delay like my older AL1200, you had to listen to the > input monitor on the MP if you were sending with a key. Listening to > the actually sent signal would is so divergent from physical input at > 30 ms that many simply can not send CW with it. > > But it doesn't fix the parallel problem on SSB. > > Even if the MP's delay was working OK for CW, there is no delay for > SSB. This would require a continuous bucket brigade voice delay with > sufficient fidelity. That isn't impossible, but a lot more expensive > and complex than a faster relay. And it STILL does NOT fix all the > issues of clunk involved. This includes the recovery time from T back > to R so slow that in contests often the first baud or two of a reply > would be lost while the relay is waiting for the contacts to restore > the RX path through the amp, which now only has the spring to propel > points to normally closed state. > > IMHO to put it bluntly, any amp relay with T/R duties that won't close > in 8 ms is obsolete and needs to be replaced by something modern. > > The aftermarket mod boards will modify old tube amps for QSK, low > voltage low current T/R keying (soft key), step start power-on etc. > Amps modified with current QSK circuitry will switch quickly enough to > support VOX on SSB. All the Ameritron amps have superior aftermarket > QSK mods available, in addition to the manufacturer's own QSK option. > > W2CS helped me QSK my AL1200 with the same circuit he used to upgrade > his SB220. This was before the current crop of excellent mods were > available. No excuses. > > 73, Guy K2AV > >> On Saturday, May 30, 2015, David Raymond <[email protected]> wrote: >> >> I'm running an older borrowed K3 to get various I/O issues worked out while >> awaiting arrival of my K3S. I am interfacing the K3 into an older tube amp >> with large open frame relays for antenna IN and OUT. The maximum TX DELAY >> limit of 20 ms on the borrowed K3 is not enough to avoid hot switching the >> amp output relay contacts. I had the delay in my old FT1000MP set for 30 ms >> which was adequate with some margin (it had a max delay of 40 ms I believe). >> Are there any options in newer K3's for more than 20 ms of TX DELAY? >> Hopefully the K3S will have more than 20 ms or my options for QRO are QRT. . >> hi. 73. . . Dave, W0FLS >> ______________________________________________________________ >> Elecraft mailing list >> Home: http://mailman.qth.net/mailman/listinfo/elecraft >> Help: http://mailman.qth.net/mmfaq.htm >> Post: mailto:[email protected] >> >> This list hosted by: http://www.qsl.net >> Please help support this email list: http://www.qsl.net/donate.html >> Message delivered to [email protected] > ______________________________________________________________ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:[email protected] > > This list hosted by: http://www.qsl.net > Please help support this email list: http://www.qsl.net/donate.html > Message delivered to [email protected] ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[email protected] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to [email protected]
