Just did some shopping on the Internet and found transfer switches by Teledyne
starting at about $275. Did not find any Birds, used or otherwise, and the
Transcos I found were in the $800 range. I confess this was a very quick
search.
Interesting that many if not most of them require 28 VDC. Anyone know why? Is
that a marine application? These seem too heavy for aviation.
The subject is of interest because I have two MFJ SPDT switches, neither of
which I particularly like. One of them works fine if the switch knob is
toggled back and forth a few times. And that’s the one that’s been indoors all
its life. Anyone found something DPDT, store-bought and acceptable, in a
moderate price range?
Ted, KN1CBR
------------------------------
Message: 22
Date: Mon, 2 Jan 2017 17:17:46 +0000
From: Richard Fjeld <[email protected]>
To: "[email protected]" <[email protected]>
Subject: Re: [Elecraft] {OT} - Variation on use of a coaxial switch
(stan levandowski)
Message-ID:
<co2pr16mb0121fbc4083b15a3bd853cc1bf...@co2pr16mb0121.namprd16.prod.outlook.com>
Content-Type: text/plain; charset="Windows-1252"
This sounds the same, and I made it to protect the front end of each
radio by switching the radio not being tested to my dummy load in case
one of the radios should transmit. I intended my switch for receive
comparisons. I am surprised the commercial switches can handle a
kilowatt and provide adequate isolation. I wouldn't want to use that
kind of power with the switch I made.
I didn't know about the switches you mention. I thought there should be
a need for them, so I called MFJ. I like to protect my equipment. I
know guys who don't think this way. Maybe MFJ didn't sell any and
discontinued them. At the time, I thought they described them rather
vaguely, missing the whole purpose. Maybe I haven't found them on their
website now.
Dick, n0ce
On 1/2/2017 7:06 AM, Charlie T, K3ICH wrote:
> Several companies (Bird, Transco) make what you describe. It is a four
> terminal coax relay called a "Transfer Switch" that for example, connects
> any two antennas to any two radios, but never at the same time. In other
> words, radio A connects to antenna 1, and at the same time, radio B
connects
> to antenna 2. Activating the switch ( either mechanical or electrically
> activated) changes the condition for A to 2 and B to 1. Most are good
for a
> kilowatt well up into the UHF ranges. For HF, I made one using a heavy
> DPDT relay.
>
> 73 Charlie k3ICH
>
>
------------------------------
Message: 23
Date: Mon, 2 Jan 2017 12:32:49 -0500
From: Don Wilhelm <[email protected]>
To: [email protected]
Cc: [email protected]
Subject: Re: [Elecraft] KXPA100 with PX3
Message-ID: <[email protected]>
Content-Type: text/plain; charset=utf-8; format=flowed
Ray,
Have you tried running the TX Gain Calibration on the KX3?
It may be that the KX3 wattmeter is not well calibrated.
If you do the TX Gain Calibration manually, it must be done on each band.
The KX3 Utility automates the process.
73,
Don W3FPR
On 1/2/2017 11:55 AM, [email protected] wrote:
> Don and others,
>
> The good news is that you were right: the RJ-45 connectors in the
> control cable were not making good contact. I fixed that and PA ON
> operation of the KXPA100 is now working.
>
> The bad news, however, is that in Basic operation with PA OFF, the
> KX3/KXPA100 puts out full power, but the most I can get out of it with
> PA ON is 50-60 watts. The attenuator is set for OUT/AUTO and there is
> no more than 1 or 2 watts reflected power.
>
>
------------------------------
Message: 24
Date: Mon, 2 Jan 2017 12:42:49 -0500
From: [email protected]
To: [email protected]
Cc: [email protected]
Subject: Re: [Elecraft] KXPA100 with PX3
Message-ID: <[email protected]>
Content-Type: text/plain; charset=utf-8
Hi Don,
I tried that but an external wattmeter confirmed the KXPA100 forward and
reflected power readings. Something in the KX3 is holding down the power
output when PA is ON, but not when PA is off.
73 Ray W2RS
-----Original Message-----
From: Don Wilhelm <[email protected]>
To: rsoifer1 <[email protected]>
Cc: elecraft <[email protected]>
Sent: Mon, Jan 2, 2017 10:33 am
Subject: Re: [Elecraft] KXPA100 with PX3
Ray,
Have you tried running the TX Gain Calibration on the KX3?
It may be that the KX3 wattmeter is not well calibrated.
If you do the TX Gain Calibration manually, it must be done on each band.
The KX3 Utility automates the process.
73,
Don W3FPR
On 1/2/2017 11:55 AM, [email protected] wrote:
> Don and others,
>
> The good news is that you were right: the RJ-45 connectors in the
> control cable were not making good contact. I fixed that and PA ON
> operation of the KXPA100 is now working.
>
> The bad news, however, is that in Basic operation with PA OFF, the
> KX3/KXPA100 puts out full power, but the most I can get out of it with
> PA ON is 50-60 watts. The attenuator is set for OUT/AUTO and there is
> no more than 1 or 2 watts reflected power.
>
>
------------------------------
Message: 25
Date: Mon, 2 Jan 2017 10:45:00 -0700 (MST)
From: Bob N3MNT <[email protected]>
To: [email protected]
Subject: Re: [Elecraft] KXPA100 with PX3
Message-ID: <[email protected]>
Content-Type: text/plain; charset=us-ascii
What band are you seeing this reduced power out on. It will most likely be
different for each band.
--
View this message in context:
http://elecraft.365791.n2.nabble.com/KXPA100-with-PX3-tp7625187p7625370.html
Sent from the Elecraft mailing list archive at Nabble.com.
------------------------------
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