[ARC5] Tube Conditioning

[Robert Eleazer]

Dennis:

Yes, that is what I thinking.  I have never done this before when I replaced the finals in my TS-520 and TS-820S or what little I have done with my HW-100 - and never had a problem.  These 6883B's look superb and since the latest TS-520 I am repairing is something of a "Junkyard Dog" of a rig (the result of a previous owner's incomplete repair attempts), I figured I will give the 6883B's a try.  But no doubt those tubes have been sitting around for who knows how long, so I wanted to reactivate the Getter.

Fortunately I have a LV DC and HV DC power supply I built on an old TV chassis in the early 80's that was last used to run a Type 12 receiver.  It even has an unused 8 pin tube socket installed. I figure the using the 12VDC or AC on the filaments and the 250VDC on the plate should make a suitable tube conditioner.

Thanks,

Wayne    
  ----- Original Message ----- 
  From: Dennis Monticelli 
  To: Robert Eleazer 
  Cc: ARC-5 Maillist 
  Sent: Thursday, January 15, 2015 3:43 PM
  Subject: Re: [ARC5] Tube Conditioning


  Yes.  it is good practice to re-activate the getter so residual internal gases that have built up over the years (due to mild seal leakage and electrode outgassing) can be captured by the getter.  The getter needs to get hot and the gases need to get in motion.  Filament alone is often enough (several hours worth) but some plate dissipation (without application of HV) helps the process along.


  I replaced the finals in my TS-820 with NOS 6146B's and did not do this.  One of more of the tubes arc'd a couple/three times when I applied power for the neutralization step.  No doubt these very brief HV-shorting arc's blasted off some cathode....not good.  I have since learned my lesson.

  Dennis AE6C






  On Thu, Jan 15, 2015 at 11:14 AM, Robert Eleazer <releazer at earthlink.net> wrote:

    I have a set of five NOS 6883B's in an original sleeve I bought on ebay. Total cost including shipping came to about $5.00 per tube.

    I want to use two of the 6883B's in a TS-520 I am repairing and have modified for 12V parallel filaments.  I understand that it is a good idea to crank up the filaments and apply some B+ to condition those tubes for a bit before use.

    Can anyone explain that process again?

    Thanks,

    Wayne
    ______________________________________________________________
    ARC5 mailing list
    Home: http://mailman.qth.net/mailman/listinfo/arc5
    Help: http://mailman.qth.net/mmfaq.htm
    Post: mailto:ARC5 at mailman.qth.net

    This list hosted by: http://www.qsl.net
    Please help support this email list: http://www.qsl.net/donate.html



  No virus found in this message.
  Checked by AVG - www.avg.com
  Version: 2015.0.5645 / Virus Database: 4260/8936 - Release Date: 01/15/15