I did quite lot of research about protective limiters. The best solution
found is to use the special TVS diodes RClamp2502L by Semtech which
incorporate surge rated, low capacitance steering diodes and a TVS diode
in a single package. During transient conditions, the steering diodes
direct the transient current away from the protected input. The internal
TVS diode clamps the transient voltage to a safe level. The low
capacitance array configuration allows the user to protect up to two
high-speed data lines.
RClamp2502L can be used directly "in-line", no additional components
needed. A new type of "RX front end saver" with Semtech's RClamp2502L is
in preparation.
73,
Martin, OK1RR
Dne 11. 10. 19 v 13:49 N4ZR napsal(a):
Array Solutions no longer handles the K9AY components, which actually
came from K9RU's Wolf RF Systems. It looks like the ICE limiter is
still out there, and reasonably priced, but I have no idea whether it's
a good design - it's pretty old - or just a pair of diodes back to back.
73, Pete N4ZR
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On 10/10/2019 10:08 PM, Alan Swinger wrote:
I use a Model 197 RF Limiter/Arrestor by Industrial Comms Engineers
for my K9AY Loop. I think I got it from DX Eng ~ 10 yrs ago, but also
chk w/ Array Solutions since I think they now handle the K9AY Loop. -
Alan K9MBQ
-----Original Message-----
From: N4ZR <n4zr@comcast.net>
Sent: Oct 10, 2019 9:30 PM
To: topband reflector <Topband@contesting.com>
Subject: Topband: Protecting an Array Solutions K9AY Loop from
Transmitted RF
I'm in the process of building up a K9AY loop, using the Array Solutions
boxes, and it occurred to me that I probably need to work out some way
to protect the preamp in the shack-end box from transmitted RF,
particularly since the K9AY loop is only about 60 feet from the vertical
leg of my inverted L and I'll be running 1500 watts.
I can see maybe cutting off the DC to the preamp, but figure that won't
be enough. Alternatively, I can probably work out a way to either open
or short the feedline coming into the indoor box where the preamp is.
Any advice as to which would be best (opening or shorting)? I only have
one spare transistor.
Advice much appreciated
--
73, Pete N4ZR
Check out the Reverse Beacon Network
at <http://reversebeacon.net>, now
spotting RTTY activity worldwide.
For spots, please use your favorite
"retail" DX cluster.
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