[Amps] L4B startup after a long sleep?

[Bill Weaver]

I'm about to do the same thing with an Alpha 86. I thought it may be a good idea to remove the tubes until the caps have proven good then re-perform the exercise with the tubes in place.
 

 
Bill - WE5P
 
 
 

 
 
 
 
 
>  
> On Dec 11, 2018 at 23:42,  <Stan Gammons>  wrote:
>  
>  
>  I would set the meter to grid current and use a variac to first power it up. Unless you have a 240 volt AC variac, you may have to rewire the power supply and RF deck for a 110 volts AC variac. There might be a loud bang if one plugs the amp in and just turns it on. Tubes could be gassy from setting so long and arc over when full plate voltage is applied. Harbach makes a replacement power supply board for the L-4B and the L-7. I think that board is what I have in my L-4B power supply. Good luck with the amp. The L-4B is a nice old American made amp. 73 Stan KM4HQE On 12/10/18 4:53 PM, Ray LaRue wrote:  >  The local club here has inherited a very nice L4B amplifier that we  >  suspect hasn't been run in about 10 years or more. On a scale of 1 to  >  10 with 10 being new, this is a very nice 9. I have been asked to  >  reform or replace the filter caps and bring it up on line.  >   >  As I've never worked on an L4B, I would appreciate any experienced  >  tips or no-nos, as !
 I begin t
o dive into it.  >   >  Any assistance would be appreciated.  >  73,  >  Ray, W4BYG  >  _______________________________________________ Amps mailing list Amps at contesting.com http://lists.contesting.com/mailman/listinfo/amps 
>