Hi Carl;
Thanks for the reply.
My "Instruction Book" is dated (4th Edition) 15 November 1961.
On my page 1-5 I find "The r-f cable supplied for connecting the 32S-1,
KWM-2/2A, or KWM-1 to the 30L-1 is 20.5 feet long. DO NOT cut this
cable. This length is Optimum to maintain the low-distortion figure for
which the equipment was designed."
It appears there was a change made between 1961 (round) and 1963. If you
have any idea as to the change please tell me as I would like to up-date
my Amp. I've got several Amps here and the 30L-1 is the one I use the most.
pete, kn6bi
Peter Gerba
pgerba@crl.com
On Fri, 16 May 1997 km1h@juno.com wrote:
>
> On Wed, 14 May 1997 19:50:32 -0700 (PDT) Peter Gerba <pgerba@crl.com>
> writes:
> >I have a 30L1 question... maybe Tom or Carl can help.
> >
> >I have a Round Emblem model. I was told that the RF cable used to
> >connect the Xmiter (KWM2 etc) to the input of the 30L1 was of critical
> length.
> >It was explained that the Amp could go into runaway on 21 Mhz and above
>
> >if this cable was not used.
>
> That is a bunch of BS Pete. I use a 6' length of RG8X for all my exciter
> (TS-940) to amplifier work on the repair bench. Never any instability.
> Any one who tells you differently obviously doesn't know that amp very
> well. The only problem in the 30L1 is with Svetlana ceramic base 811A's,
> they have too much output C to tune 10M.
>
> One thing you must remember....the 30L1 was designed for broadband
> service, not just the ham bands. Therefore the input circuit is a
> compromise. The 10M band for instance tunes 22-30MHz and the input
> matching values are a compromise; particularly since only the coil is
> variable. That long input cable was just a bit of a fudge factor. If
> your amp came from the military, it would be advisable to realign all the
> input coils.
>
> Another thing...that amp was made in huge quantities; had a damn good
> reliability record and survived the typical non-technical military
> operator. How many thousand are still in operation?? Tells you something
> about the design!
>
> >>From the Collins 30L1 Manual page 1-2, Table 1-1, R-f input cable
> >426-5079-00, page 1-0, under "notes" #6 " This cable is furnished with
> 30L-1 in 20.5 FT length. Do not cut".
>
> My manual says no such thing as "do not cut" on any page and it is dated
> 1 March 1963.
> If you have the manual go read a bit further. On page 1-5 it says the
> cable may be shorter for convenience; at least in the Rev here.
>
> SNIPS
>
> 73....Carl KM1H
>
> --
> FAQ on WWW: http://www.contesting.com/ampfaq.html
> Submissions: amps@contesting.com
> Administrative requests: amps-REQUEST@contesting.com
> Problems: owner-amps@contesting.com
>
--
FAQ on WWW: http://www.contesting.com/ampfaq.html
Submissions: amps@contesting.com
Administrative requests: amps-REQUEST@contesting.com
Problems: owner-amps@contesting.com
|