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[TowerTalk] Antenna Relay -

Subject: [TowerTalk] Antenna Relay -
Date: Sat, 12 May 2007 12:48:34 EDT
List-post: <>
With regard to choice of conventional "clapper" type relay to use for  RF 
circuits note there are several considerations to be evaluated.   Power 
RF Voltages/Currents and Frequency.  Below 30 mHz most of  the popular relays 
available will work with a little care in dressing the leads  to the 
contacts, and PCB mounted relays usually solve that issue.  
The material separating the leaf springs may determine the "voltage"  rating, 
and the leafs and contact buttons are a factor in current handling.  (Power). 
Frequency factors are more to do with the physical design and dimensions of  
the leafs and wires that connect the leaf springs to it termination.  I  
looking at the relays used in the Ameritron antenna switch, and those on Jays web, and most relays  
offered, there is one very big difference that would be a 
factor in upper  frequency range use and maybe power handling.
Note the web connecting the two leaf springs together.  This provides  a very 
low inductance path for RF currents to flow.  Since this relay is a  DPDT it 
permits paralleling the contacts for high current handling.  Also  note the 
relays shown on Jay's site do not appear to be PCB mounting type which  may add 
more "lead" inductance when making connections.
Ratings are part of the selection criteria, but also how it is mounted and  
constructed may be more important depending on the end use.  I don't think  the 
relays from Jay will have the high frequency range of the Ameritron  relays.  
I would try going to MFJ and seeing if they will sell you relays  as 
replacement parts, somebody has to make repairs and do replacement.
Norm W4QN

From: "Tom McAlee"  <>
Subject:What relay do Ameritron and Array Solutions  use in their coax 
To: "W7CE" <>, _towertalk@contesting.com_ 

I  don't know the manufacturer.  But, if your goal is to obtain some, you can 
buy those relays from Array Solutions:

Scroll to the  bottom.  You'll see he sells the relays individually for $45 
each...  same relays used in the RatPak, SixPak, etc.

If you really just want to  know who makes them, perhaps if you call or email 
Jay he will tell  you.

Tom, NI1N

----- Original Message ----- 
From:  "W7CE" <>
To: <>
Sent:  Friday, May 11, 2007 9:24 PM
Subject: [TowerTalk] What relay do Ameritron and  Array Solutions use in 
coax switches?
>I am designing a custom  coax relay.  I own a couple of Ameritron RCS-8V
> switches and am  pretty happy with them, especially since they are rated to
> 250+  MHz.  I recently looked inside an Array Solutions Ratpak and  noticed
> that it uses exactly the same relay as the Ameritron.  I've  been trying to
> figure out who is the manufacturer of this particular  relay and after much
> time with Google have hit a dead end.  Both  switches use a form X 
> (shorting bar mounted on the two arms at the  contacts) SPDT, 12V 
open-frame relay 
> with the following marking:  X99KP  12VDC  RSCO.  It appears the X99KP is 
> part  number and RSCO is the vendor name or code.  Does anyone know who 
> this relay?  You can see a picture of it at
> Thanks & 73,
> Clay   W7CE

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