The Tohotsu relays are very popular worldwide for QRO at VHF/UHF. I use the
CX-600N at 222 and the CX-520D& CX-540D from 432 thru 2304 MHz.
Selected for the excellent stated and measured isolation.
I havent experienced any hot switching or blown preamps in the 25 or so
years Ive used them.
Carl
KM1H
----- Original Message -----
From: "Mike Willis" <m.j.willis@rl.ac.uk>
To: <amps@contesting.com>
Sent: Wednesday, April 02, 2008 4:24 PM
Subject: Re: [Amps] Amps Digest, Vol 64, Issue 5
> For amplifiers using mechanical coaxial relays, TX/RX switching time
> depends mainly on the settling time of the coaxial relay. Here are some
> manufacturers figures. An sequencer will need to delay by at least this
> amount, preferably a bit more.
>
> Tohotsu relays are very common. The CX540 is the one I see most
> frequently and it takes 20mS to engage and 15mS to release.
>
> The CX230, CZX3500, CX600, CX800, CX140 and CX120 are also very commonly
> used in amateur applications (because they are good value for not too
> much money). They all specify 20mS.
>
> SSB electronics (Germany) do a high power range of relays. These specify
> 30mS for the HF400 series, 40mS for the HF500/1500 series and 50mS for
> the HF4000 series.
>
> Just about all the amplifiers I have seen use one of these relays or
> close equivalent. Worst case is 50mS but more likely 20mS.
>
> I do not have figures for Jennings but they are likely to be similar.
>
> Mike
>
> PS - PLEASE don't reply telling us PIN switches are better - I don't
> care as that was not the question!
>> Date: Wed, 02 Apr 2008 10:36:48 -0400
>> From: Greg - AB7R <ab7r@cablespeed.com>
>> Subject: Re: [Amps] Relays
>> To: '' amps '' <amps@contesting.com>, John/K4WJ <k4wj@bellsouth.net>
>> Message-ID: <0B.ED.16396.00A93F74@mxo5.broadbandsupport.net>
>> Content-Type: text/plain; charset="us-ascii"
>>
>> Can someone tell me what the extremes are on typical t/r relays in amps?
>> Many
>> newer amps seem fine with a 10ms delay from keydown to RF. I'm wondering
>> if there
>> are amps that are even quicker than this and what some worse case
>> scenarios are
>> with older amps.
>>
>> Thanks!
>>
>> -------------------------
>> 73,
>> Greg - AB7R
>> Whidbey Island WA
>> NA-065
>>
>>
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