[OKDXA] Amp Fixed (I Hope)

[Kim Elmore]

I’ll check to see if I have a suitable 20 A fuse. How many do you need?

73,

Kim
N5OP

"People that make music together cannot be enemies, at least as long as the music lasts." -- Paul Hindemith

> On Jan 8, 2023, at 9:24 PM, GARYLM at kiamichiwb.org wrote:
> 
> 
>    
> 
> 
> HI KIM, 
> Glad you found the problem, I turned my amp on yesterday and it blew incoming voltage fuse on warm-up, hope to find another 250v 20amp fuse tomorrow, hope that is all that is wrong.  Fuses and amp are over 30yrs old.
> Sitting here listening on 30m to stations calling FT8WW, but not hearing him here. Looks like this is going to be one I miss.
> Good luck working him and the TN8K, he is on 3.525 now but cannot hear them.
> 73
> Gary - WQ5R
>  
> 
> 
> On Sun, 8 Jan 2023 18:56:05 -0600, Kim Elmore <cw_de_n5op at sbcglobal.net> wrote:
> 
> I found that I hadn't escaped the flashover event unscathed: my rx was
> dead with the amp enabled . I installed a QSK-5 PIN diode T/R switch in
> my amp so that I could do QSK at 1.5 kW. Since I'm not in a multi-multi
> environment, I needn't worry about any IMD issues that can occur with
> PIN diode T/R switches in high RF environments. The rx path is protected
> by two grain-of-wheat bulbs and if the current in the rx path gets more
> than a few mA, these blow. They were blown. It's an easy fix.
> 
> A careful internal inspection revealed no issues. I hadn't been diligent
> at all about cleaning the amp interior the past few years and there was
> a fair buildup of dust inside and around the RF deck. I suspect, but
> can't prove, that the flashover was caused by dust in and around some of
> the HV areas, perhaps near the base of the plate choke. I saw no scorch
> marks, so I don't know for certain, but it's all I can come up with.
> 
> I did learn that the fuses in the line input to the amp, two 15-ABC
> fuses are pretty expensive. But! I found someone selling six 5-packs of
> them on e-pay for $1.00 each. So, I got 30 15-ABC fuses for $6 (six
> 5-packs) plus $8 shipping. These guarantee that I'll never see this
> happen again!
> 
> I only need to put the cover back on, secure it the 22 4-40 screws, and
> I'll be back where I was.with
> 
> 73 & CU in the Pileups,
> 
> Kim N5OP
> ______________________________________________________________
> OKDXA mailing list
> Home: http://mailman.qth.net/mailman/listinfo/okdxa
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:OKDXA at mailman.qth.net
> 
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
>  
> 
> 
> 
> ______________________________________________________________
> OKDXA mailing list
> Home: http://mailman.qth.net/mailman/listinfo/okdxa
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:OKDXA at mailman.qth.net
> 
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html