If you don't care about arcing the relay contacts or generating a burst
of nasty, broad signal when you key up,
then of course you'd be right.
If your transceiver could handle the switch voltage/current/inductive
spike of the amplifier relay key line,
you'd be right again. In your case, though, since the SB-200 uses a 120V
relay coil, I somehow doubt the F3K's
switching transistor would tolerate that for long without the isolation
box. Perhaps someone from Flex knows the actual spec.
Not sure how "overly cautious" applies here?
73,
Jim N7CXI
On 9/2/2013 7:01 AM, Lee Mushel wrote:
Interesting thread. I suspect that the topic is simpler than people
might want it to be. When I started to use the Flex3000 with a
rather heavily used SB200 some three years ago I wondered about the
possibility of mixing tube and solid-state voltages and was told to
"not worry about it." But being a conservative person I bought a
"Sunlight" isolation relay box (no longer available), never adjusted
anything and have never had any problems. But then I've long felt that
people tend to be overly cautious which can lead to wanting to be
"taken care of."
73
Lee K9WRU
----- Original Message ----- From: "Jim Barber" <audio...@q.com>
Cc: <flexradio@flex-radio.biz>
Sent: Sunday, September 01, 2013 10:14 PM
Subject: Re: [Flexradio] TXOut Delay.
50ms is probably around the minimum for an SB-200.
It all depends on the relay(s). In the case of the SB-200 it's an old
open-frame type, very slow. Amps advertised for "QSK" use often have
vacuum relays, which can switch many times faster.
If you're running SSB, keep in mind that hotswitching the antenna
contacts is the major issue, but not the only one. Some amp designs
(not the SB-200) have a separate relay for the tube bias, which is
often buffered with a simple R/C network. The point is that you
shouldn't put drive on the tube(s) before the operating bias has had
time to switch from cut-off to operate. In the case of the SB-220 for
example, the cutoff bias is set to a unnecessarily high voltage as a
matter of convenience, which makes the situation worse.
My .02,
Jim N7CXI
On 9/1/2013 8:22 PM, Steve Sterling wrote:
Steven-- I was kinda waiting to see what others thought, but haven't
seen any response in 24+ hours.
I have mine set at 50ms. That's a pretty reasonable time for power
and antenna relays to pull in and get seated.
I originally started at 100ms, but the delay was noticable-- not
long, but you could kinda tell it was there. I can't tell 50ms at
all, except a little on CW. I start getting faults in my amp with
less than 20-25ms of transmit delay on 80 and 40 meters. 20 meters
I could set it at 0ms and it never faults. Go figure.
Steve WA7DUH
On 8/31/2013 7:52 AM, Steven Hess wrote:
I've got a SB 200 with a interface for proper keying from a modern
rig to
the relay installed.
What should I set the TXOut delay for to make sure the relays are
properly
closed before I pass RF to the amplifier? I've got it set for 7 In the
General Options tab of PowerSDR right now.
Steven
_______________________________________________
FlexRadio Systems Mailing List
FlexRadio@flex-radio.biz
http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz
Archives: http://www.mail-archive.com/flexradio%40flex-radio.biz/
Knowledge Base: http://kc.flexradio.com/ Homepage:
http://www.flexradio.com/
_______________________________________________
FlexRadio Systems Mailing List
FlexRadio@flex-radio.biz
http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz
Archives: http://www.mail-archive.com/flexradio%40flex-radio.biz/
Knowledge Base: http://kc.flexradio.com/ Homepage:
http://www.flexradio.com/
_______________________________________________
FlexRadio Systems Mailing List
FlexRadio@flex-radio.biz
http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz
Archives: http://www.mail-archive.com/flexradio%40flex-radio.biz/
Knowledge Base: http://kc.flexradio.com/ Homepage: http://www.flexradio.com/