[SBE] Continental 816

[James Keightley]

Barry,
I was involved in replacing one of these veteran transmitters.  The pull
went to a transmitter salvage person.   Should you need a hard to find
part, give me a call and I can see if  it might be available near here.

Best of good luck.  I love to work on those old tube (hollow state)
transmitters.

Jim Keightley EFE
Keightley Company LLC
150 Sleepy Hollow Rd
White Salmon, WA  98672
          509 493 3403
      Technical Service to
Small Market Radio Broadcasters


On Tue, Sep 2, 2014 at 9:54 AM, George Corso <gcorso at bellsouth.net> wrote:

> Barry.
>
> Have you moved the deck above the PA  tube. 1/8" can make a difference
> trying to get all the "veteran" parts to play nice together.
>
> Be safe!
>
> G
>
> -----Original Message-----
> From: SBE [mailto:sbe-bounces at sbe.org] On Behalf Of Barry Thomas
> Sent: Thursday, August 28, 2014 12:03 AM
> To: SBE Member Discussion List
> Subject: [SBE] Continental 816
>
> I haven't seen much activity on this list in a long time. I hope the brain
> trust is still active.
>
> It has been soooo long since I've troubleshot a Continental 816 with a tube
> driver stage i really don't remember the old skill set.  Some advice on the
> first things to look at would be great.
>
> The problem:  I am not getting enough power out of the transmitter ....
> Only
> 80% with it running at full blast.  The final is new and good and tunes
> well.
>
> I'm fairly certain it's driver-related.
> At first I thought it was just bad 4cx250b tubes...They were old.  I
> Replaced them but still have the same results. Both tubes are operating and
> seem balanced.  I've got a good match from the exciter into the driver
> stage
> and the driver plate tunes into the final, although PA grid current is low
> (of course).
>
> Driver and PA Plate and screen voltages are fine. Cathode currents of the
> two drivers are balanced but low. In fact All driver current readings are
> low by 50-70% EXCEPT driver screen current reading which is PEGGED.
> Backing
> off the power to 40% final output un-pegs the meter but it is still at the
> max scale. I know I should remember exactly what this means but it has just
> been too long.  Or maybe the meds have killed too many brain cells.
>
> I am hoping with your help I can short circuit some of my re-education on
> this old box.
>
> Any suggestions on the FIRST things I should check in the driver stage?
>
> Thanks for your suggestions.
>
> Barry Thomas, CPBE DRB CBNE
>
> Sent from my iPhone 5
>
>
> Barry Thomas, CPBE DRB CBNE
> barryt at sbe.org
> (323) 841-0682
>
> Sent from my iPhone 5
>
>
> _______________________________________________
> The SBE Roundtable, SBE at sbe.org
> To unsubscribe, go to http://seven.pairlist.net/mailman/options/sbe
>
> http://seven.pairlist.net/mailman/listinfo/sbe
>
> _______________________________________________
> The SBE Roundtable, SBE at sbe.org
> To unsubscribe, go to http://seven.pairlist.net/mailman/options/sbe
>
> http://seven.pairlist.net/mailman/listinfo/sbe
>



-- 
*    Jim Keightley*  EFE
  Technical Service to Small
  Market Radio Broadcasters
Site Development & Management
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://seven.pairlist.net/pipermail/sbe/attachments/20140902/ae2ff446/attachment.html>