Hi Bill!
Well, I'm not an 'expert' on much of anything, and don't have an Orion, but
I can describe my observations on how I think the QSK functions are
'supposed' to work.
The RX to TX keying sequence should go:
Key closure:
1) RX mute
2) Antenna changeover to TX
3) Amplifier cutoff bias release
4) Transmitter in TX
and the TX to RX sequence:
Key opening:
1)Transmitter in RX
1a- slight delay (anticipate possible next CW character)
2)Amplifier cutoff bias applied
2a- slight delay (allow finals to settle into cutoff)
3)Antenna changeover to RX
4)RX unmute
>From what I understand, the concept hierarchy:
- Prevents switching the changeover relay when RF power is applied
- Prevents amplifier from transmitting into an unsettled antenna relay
- Prevents amplifier from being driven when there's cutoff bias
- Prevents station from dropping out of TX mode when there's another
character close behind
I'm not sure how the radio's "QSK delay" parameter affects sequence 2A, but
I know 1a should be set according to your fist and preferred rate. Someone
with a really good fist could set the delay time very tight, as they'll
keep their character and word spacing very consisent. I, on the other
hand, have a fist made of re-heated lasagnia, so I'll set it a little
loose. The trade-off is that your RX 'window' between transmits will
become short, or nonexistant, so you won't be able to 'hear between'
letters or words. This hasn't been a problem for me, because I'm such a
poor copy that I'm most concerned that I'm not transmitting atop someone.
If I let up, and hear another op TXing, I drop back and wait. Really good
fists will actually be able to recover some of the QSK-RX'd sound... I'm
just not that good.
The setpoint for 2A is really more dependent upon the amplifier,
transmitter, and changeover relay. I'd think that some amplifiers are a
bit slower to respond to cutoff bias changes than others, and it may, or
may not be a significant timespan. Regardless, if the tubes aren't quite
cut-off, there's chance of a bit of RF still coming out of the finals 'till
cutoff is complete. Again, I don't know the details- just what I've
encountered in lots of theory reading. I don't believe there'd be too many
machines with this as an adjustable parameter.
On T_T transcievers and amps, there's a lead that goes from the transciever
to the amp, which energizes the amplifier's transmit circuit- the
changeover relay, and bias control. IN the amplifier, on the relay, is a
set of contacts which go back to the transciever, to tell the transciever
that the amp has been put in transmit position, and bias released. This
second lead prevents the transmitter from transmitting into an un-ready
amplifier. I've run this on my Omni VI/Centurion combo since I got it, and
I don't think there's any provision for delay. I built a similar
arrangement for another tranciever/amp system, and made the relays do all
the timing... of course, it's not lightning-fast, either...
DK :-)
At 04:28 PM 09/19/2003 -0400, you wrote:
>I posted this on the Orion reflector but thought I would try here also.
>
>I finally decided to hook up my QSK amp to see how it works with
>Orion. Amp Supply uses a vacuum relay, driven by KEY IN from a keyer and
>then connects the amp's KEY OUT to Orion's AUX I/O PTT line. I assume this
>is done to insure that there are no delay issues. I did adjust Orion's CW
>QSK Delay to 6% which sounds better than 0% in the monitor, but I suspect
>there is a better way to adjust this.
>
>Orion recommends doing it the other way around, i.e. key the radio directly
>with the keyer, send TX OUT 1 to the amp's KEY IN, and then send the amp's
>KEY OUT back to Orion's TX EN 1.
>
>I haven't tried the second way, but does anyone have an opinion as to which
>is best, and how to adjust CW QSK Delay? I last used QSK with an amp in
>about 1960 using the EF Johnson T-R switch, so I'm out of touch with how
>these things work these days. I'm still inclined not to use QSK in
>contests for reliability reasons (you only get so many relay cycles in a
>relay's lifetime) but may play around with it a bit for DXing.
>
>73, Bill W4ZV
>
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>
---------------------------------------------------------
73's from KW0D Dave in LeClaire, Iowa
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