Re: {Collins} 30S-1 Plate Reactor replacement

Hi Bill and so good to hear from you.  I've been doing too much lurking
here and not enough contributing.  So, will cc the list on this.

We are in complete agreement on the size/current capability of the
transformer.  As I noted in my original post, the a properly driven 30S-1
is only loaded to 350MA in order to make 1KW DC input.  I was always taught
that running a component at 80% of its capacity or less was a prudent path
to maximizing its life.   So, one example might be a cap rated at 100VDC
should never see more than 80 working volts DC or be presented with more
that +- 80VAC, P-P.

Back to the 30S-1.  A current 80% of the capacity of L-202 is 400MA, so at
350MA, there is still plenty of headroom in that reactor provided the
amplifier is loaded to the 1KW DC input spec.  You note the extremely valid
point on observing the cooling system limits.  I have about a 3 page letter
from Warren Bruene, W5OLY in response to a question I asked about whether a
4CX1500 would be a viable replacement for the 4CX1000.  At the time, I was
concerned about opening the grid on the '1000 and saw that the '1500 grid
was a good bit more tolerant.

To distill Warren's response, he simply encouraged the amplifier be driven
at spec whereupon grid destruction and cooling issues would not be an
issue.  Also, he went into some detail in explaining how the integrity of
the amplifiers superb specifications would be preserved when the 30S was
operated at spec.

My issue is currently one of noise; am not looking for more output than
spec.  Turn on the HV, simply key the amplifier without applying any drive
and that reactor buzzes like mad. I verified it was the source of the noise
by placing a wooden dowel against one of the bells and the other end
against my ear then keying the amplifier (thanks Floyd, W8RO suggestion).
There is no doubt where the noise is sourced.  I tightened those laminate
bolts which I could reach; the two on the top which had no effect.  I spoke
to a ham who professed to have "worked on dozens of 30S-1's" in the
military said he solved the problem by installing a new reactor rated at
1.5A which solved all the buzzing issues and further, the stock unit was
undersized at 500MA.   That the stock part was undersized motivated my
hmmmmmm..... comment for all the reasons above and your advice is well

A cursory inspection reveals that L-202 may be difficult to remove.
Difficult to the point that the RF deck may have to be removed.  My revised
plan was simply to order one from the folks who took over Peter Dahl and I
see they stock them at $310, pull the old one and immediately replace it
with the new part.  However, at the price of a new reactor, maybe a "plan
B," is in order - remove the stock unit and have it dipped.  Maybe then
I'll be rid of the 30S-1 "bee hive" currently in the shack.

Chuck, WA4HHG

On Thu, Nov 27, 2014 at 10:34 PM, Bill Carns <wcarns@xxxxxxxxxxxxx> wrote:

> Hi Chuck and Happy Thanksgiving.
> I would not say that transformer is undersize at all. The fact is that the
> amp is cooling limited due to the Plate Input power limitation at the time
> of its design and the transformer has plenty of starch in it.
> Me, I would just have the one you have evacuated and re-impregnated after
> tightening the laminate bolts. I recommend Gary for this and it will be
> much
> cheaper than trying to find a replacement.
> Are all of the bolts in place (and tight) that mount both the choke and the
> plate tranny?  Then try just tightening the laminate bolts if they will
> turn.  We rarely see that transformer fail. Some "humming" is normal under
> full key down but that is to be expected.
> Regards and good to hear from you.
> Bill Carns, N7OTQ
> Trustee K0CXX
> President, Collins Collectors Association
> Editor, Signal Magazine
> Wimberley, TX
> 512 618 2762  (Cell)
> 512 847 7010  (Home)
> -----Original Message-----
> From: Collins []
> On
> Behalf Of Charles Rippel
> Sent: Thursday, November 27, 2014 8:22 PM
> To: collins@xxxxxxxxxxxxx
> Subject: {Collins} 30S-1 Plate Reactor replacement
> I wonder if they have a replacement reactor, L-202 for the 30S-1 ?  Mine
> buzzes like mad when the HV is applied, gets worse when the amp is keyed.
> I'm told that the original is undersized, being rated at "only" 500MA.
> That comment got a "hmmmmmmm" from me.  The amplifier loads per the manual
> to 350MA so 500MA should be adequate.
> I digress, would like to get rid of the buzzing.  If I'm going to pull the
> reactor out, would rather replace it with a new part v/s sending it to be
> dipped.
> Thoughts?
> Chuck Rippel
> PS:  The R390A's, they just keep a-coming......
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