To put it simple terms:
Sun(spot) activity is low, atmo/ionosphere layers height has shrunk.
RF mirrors/ducts are lower, propagation is squished (sucks).
I remember 1958 when I could work the whole world at the same time with
10W Wehrmacht tank TX and (Windom) piece of wire for 24 hours on 10m!
Great question, Craig! I asked this question a few months ago here:
ham.stackexchange.com/questions/8940/what-is-the-cause-of-this-unusually-long-period-of-terrible-hf-band-conditions
It is NOT what the answers there claim. I have done extensive research on
this. And when I get the time and motiv
Amazon has many different types ranging from wall warts to dedicated heavy
duty supplies. I would think the wall wart would be enough to key relay and
they are inexpensive.
73, Jim K7EG
_
Topband Reflector Archives - http://www.contesting.com/_topband
Hi Jim
I'm trying to detune my TX vertical on RX, I want to use the tx out on my flex
6500 to do the switching I can add in delays using the flex software which is
handy,
So basically when I tx I want the relay to close and when I un-key it opens and
it shorts the tx antenna to ground,
It's h
So, what IS going on? Why has propagation on Top Band (and other bands) been
so poor?
An inquiring mind would like some "ed-u-macation." I missed K9LA's
presentation
at W9DXCC this year.
Craig Clark K1QX
_
Topband Reflector Archives - http://www.contesting.com/_topband
Trevor,
It’s unclear to me what you’re looking for. One transistor and a 24V power
supply can activate a vacuum relay, but are you trying to key up an
amplifier with the relay, ground a receive antenna, implement a QSK
circuit, or what? Do you want to sequence the relay to prevent
hot-switching. Wh
See February 2008 QST, an extensive article.
73, Roy K6XK
_
Topband Reflector Archives - http://www.contesting.com/_topband
Trevor
That circuit works well if you only have a 13V typical radio supply. You
can string several relays from the T/R line but remember to fit a 1N4000
type diode across the relay, + end to supply, -end to the T/R line.
It's important to take into account your linear amplifier (if you are u
I'm still looking for a way to do this can't see anything on W8JI's site
suitable and the fast relay link isn't what I'm after,
Thanks
Trevor
EI2GLB
- Original Message -
From: MR TREVOR DUNNE
To: 'topband List'
Sent: Tue, 14 Nov 2017 19:51:18 - (GMT)
Subject: Topband: Vac relay keyi
