[Elecraft] KPA500

[Joe Subich, W4TV]

On 11/5/2024 9:13 AM, Pete Smith N4ZR wrote:
> They have been quite helpful, though I will NEVER understand their
> failing to publish schematics since the K3 era.
Pete,

KPA500 schematics are (were) available on-line.  At least I have a copy
that I downloaded in March 2011

 > On 11/5/2024 8:57 AM, David Olean wrote:
 >> I figured that I would ask a few questions to get
 >> me pointed in the right direction.  Can anyone help out?

Dave,

Check your e-mail

73,

    ... Joe, W4TV


On 11/5/2024 9:13 AM, Pete Smith N4ZR wrote:
> Dave, you're probably better off asking Elecraft directly (if you 
> haven't done so already).  They have been quite helpful, though I will 
> NEVER understand their failing to publish schematics since the K3 era.
> 
> 73, Pete N4ZR
> 
> On 11/5/2024 8:57 AM, David Olean wrote:
>> I have a KPA 500 that is hardly ever used. I think I made less than 
>> ten contacts with it. As a result, I am not that familiar with it 
>> except that it worked great. I loaned it out to a friend and it came 
>> back broken. I am trying to figure out what happened. When I key the 
>> radio I see about 0.6 amps of idle current. TX Signals will pass thru 
>> OK on standby, but if I try transmitting into the amp, I see a high 
>> input VSWR  and the idle current stays constant at 0.6 amps. There is 
>> no output power.  It seems that maybe the input TR switch may be at 
>> fault. Question: What is the proper idle current for the FETS as 
>> displayed on the screen? If I had a schematic, I could dig into it, 
>> but not having that, I figured that I would ask a few questions to get 
>> me pointed in the right direction.  Can anyone help out?
>>
>> Dave K1WHS
>>