Topband: Protecting an Array Solutions K9AY Loop from Transmitted RF

[Martin Kratoska]

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
> Check out the Reverse Beacon Network
> at <http://reversebeacon.net>, now
> spotting RTTY activity worldwide.
> For spots, please use your favorite
> "retail" DX cluster.
> 
> 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 at comcast.net>
>>> Sent: Oct 10, 2019 9:30 PM
>>> To: topband reflector <Topband at 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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