[Top] [All Lists]

Re: [Amps] Alpha 77 start up

To: "Jan Ditzian" <>
Subject: Re: [Amps] Alpha 77 start up
From: "Paul Christensen" <>
Date: Mon, 21 Feb 2011 08:39:47 -0500
List-post: <">>
> "I am going to try to get some bulbs for the Alpha 77, two x 334 for the 
> meter that has none, and one x 387 for the standby button that may have a 
> burned out bulb.  Can someone tell me how to access the meter bulbs and the 
> switch bulbs?"

On the Alpha 77 series, access to the switch lamps can be accomplished from the 
front of the amp.  The easiest way is to remove the top two lenses to give you 
better access to the STBY/READY lens.  Take a small jeweler's screwdriver or 
ball point pen and press on the small indentation on the top lens (SSB/HV).  
Pull the lens while inserting the screwdriver.  The cap will come right off.  
Ditto for the second and third lenses.  The bayonet lamp will slide out to the 
left and/or right.  While you're at it, replace all of them at one time.

Replacing the meter lamps is just slightly more difficult as it generally 
requires front panel removal.  I have replaced meter lamps without panel 
removal but for me it wasn't worth the aggravation of manipulating needlenose 
pliers in such a small space.  To proceed with panel removal, follow these 

1) Unplug/remove power cord from the wall receptacle;
2) Remove top cover.  It is removed by two machine screws on the back lip of 
the top cover.  Then, slide the cover off toward the back;
3) Next, remove the top horizontal aluminum trim piece.  Remove the screws that 
can now be seen on either side.  After screw removal, the trim piece lifts 
straight up and out of the way.  You can now see better into the area of the 
meter lamps;
4) Remove both Tuning and Loading knobs with a Hex wrench;
5) Remove four #10 panel screws on the left panel, then four #10 panel screws 
on the right;
6) Note the position f the turns counter and write it down;
7) The entire front panel simply pulls out, held only by a small umbilical cord 
with a pair of mating Molex connectors.  Once the panel is pulled far enough, 
un-mate the Molex connectors;
8) The panel is now free and can be placed on a soft service for easy servicing 
of any panel components including the meter lamps.
9) Replace all four meter lamps;
10) Reverse the process for re-assembly.  However, when placing the panel back, 
note your written turns-counter reading.  As the panel is re-installed, note 
that the TUNE control mechanism is simply press-fitted with a cam against a 
Nylon disk.  Ensure that the cam is inserted into the groove of the disk.

Paul, W9AC
Amps mailing list

<Prev in Thread] Current Thread [Next in Thread>