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Re: [Amps] {Collins} 30S-1

To: "kingwood" <>, "Amp Reflector" <>
Subject: Re: [Amps] {Collins} 30S-1
From: "Carl" <>
Date: Tue, 20 Oct 2009 20:07:27 -0400
List-post: <">>
Which are all reasons why I have never had any interest in owning one.

My experience is limited to repairing maybe 5 and converting 6 to 6M 
monobanders where they have a better chance of reliability.


----- Original Message ----- 
From: "kingwood" <>
To: "Amp Reflector" <>
Sent: Tuesday, October 20, 2009 6:07 PM
Subject: [Amps] {Collins} 30S-1

> Greetings to all,
>        There is some misinformation  being passed out here about these
> tubes.  There are two common 4CX1,500 tube types, the "A", and the "B". 
> The
> "A" tube has a 25 watt grid dissipation rating but will not work in the
> 30S-1 without changing the tube socket.  The "B" tube has a 1 (one) watt
> grid dissipation and will directly replace a 4CX1,000 in a 30S-1 amp.  As 
> I
> said in an earlier post, this is a X 10 increase in grid dissipation over 
> a
> 4CX1,000.
> .
>        It is important to know, and understand, that the band switch in 
> the
> 30S-1 was never intended to see more than about 600 watts of RF.  This amp
> was designed at a point in time when US Amateurs were only allowed to run
> 1,000 watts AVERAGE INPUT power, not OUTPUT.  This band switch is made on 
> a
> thin sheet of G10 fiberglass with contact points riveted on.  My point is,
> be careful how you handle this switch, both power applied and switching. 
> I
> had to pay $500 for the last one I changed out for an RTTY operator.  In 
> my
> opinion, the 30S-1 should never be operated on any continuous mode.  High
> speed CW is also very hard on it.
>        Despite the other numerous faults with this amp, it is still around
> and quite a topic of conversation.  Ask yourself why has it not increased 
> in
> value comparable to other similar amps.  If you ever had to maintain a
> "fleet" of these amps, as with the MARS program, you will understand why.
>        I have a 30S-1 with grid drop-out mod, fused step-start,  and
> 4CX-1,500 with increased screen voltage.  With these mods, it runs 
> reliably
> in SSB but I still cringe every time I turn it on -- so many more bad
> things, than good things,  can happen every time it is turned on.
> 73 de Lon, K5JV
> 1110 Golden Bear Ln.
> Kingwood, TX 77339
> 281-358-4207
> 281-358-4234 FAX
> 281-795-1335 CELL
> _______________________________________________
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