[Hammarlund] SP600 Antenna Input

[Joe Connor]

Al's experience is much like mine. The BBODs didn't measure that badly on a VTVM but once I got them changed out, the receiver's performance was day and night, and I thought it performed well before I changed them out.

The biggest PITA was the one in that pod alongside the RF deck. I had to remove the filter chokes and the FCU to get at that one lonely BBOD.

                             Joe Connor



>________________________________
> From: Al Parker <anchor at ec.rr.com>
>To: Wes Bolin <k5apl at yahoo.com> 
>Cc: "hammarlund at mailman.qth.net" <hammarlund at mailman.qth.net> 
>Sent: Monday, March 4, 2013 5:32 PM
>Subject: Re: [Hammarlund] SP600  Antenna Input
> 
>hi Wes,
>    I agree, getting some signal thru that connection is surprising.  Maybe it'll hear much better after you get it right.
>    But, on the BBOD's, don't take your VTVM's word for them being good. If you put a little voltage across them, I'll guarantee you'll have a lot more bad.  It just finds the shorted ones.  The 5 megohm one is bad, and really any that measure any resistance at all probably are, too.  I have a AC powered bench megger that I use to check caps, usually the BBOD's show maybe 5 megs at less 50 vdc, but much less than a meg at 250v & up.  I can go up to about 800vdc on that tester.
>    How many had splits in them?  I did an SP-600 RF deck a while back that had about 15 with splits.
>73,
>
>Al, W8UT
>www.boatanchors.org
>www.hammarlund.info
>
>"There is nothing -- absolutely nothing -- half so much
>worth doing as simply messing about in boats"
>Ratty, to Mole
>
>On 3/4/2013 5:03 PM, Wes Bolin wrote:
>> I am restoring my SP600 JX26 and just pulled the RF Deck for re-capping.  J1, the antenna input jack, is a N-F connector (not twinax).  Upon
>> inspection of the RF compartment, both leads from Contact 5 and Contact 6 are going to the center pin of the RF connector!  Looks to me like
>> all the turret input coils would be shorted since the "usual" mod would be to have one lead to center pin, and the other to ground.
>> Even more puzzling is that the radio played very well before I started the restoration.
>> Any comments or ideas?
>> FYI this radio had only one defective BBOD so far:  A .01 uF that is open.  All other capacitors that I have replaced to date have between 5 and
>> 200 Meg ohms of resistance measured by my 11 Meg input V.T.V.M.  Now only have 20 to go!
>> Thanks,
>> Wes
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