The Electronics Universe

Over The Air => Ham Radio Circuits and Repair => Topic started by: uplink7 on May 08, 2018, 02:28:08 PM

Title: Old Knightkit 50 watt transmitter capacitors
Post by: uplink7 on May 08, 2018, 02:28:08 PM

Hi guys, new to this forum but really enjoy the videos on YouTube. I am restoring an old Knightkit 50 watt transmitter and want to replace the 60 year old electrolytics in the power supply. They are 8 MFD 700 volt caps. I checked the Just Radios site that has been recommended on YT but they only have up to 600 V electrolytics. The manual says the Key Up voltage on the 5U4 Rectifier is 720 volts so I don't want to use use the 600 volt variety. I'd rather not put ones in series to increase the voltage rating say 2 350 V caps to make 700 V unless I have to.
Any suggestions on where I could get suitable replacements  or what I should use instead?

Bill

Title: Re: Old Knightkit 50 watt transmitter capacitors
Post by: The Radio Shop on May 08, 2018, 06:13:18 PM

Hi Bill and welcome.
I would need to research those capacitors. 700 volt caps are rare to find these days. Have you tried Hayseed hamfest?
They may have them.

When I need caps like that I put them in series and then put a piece of heat shrink around them making it look like one capacitor.
I have not seen a knight transmitter in so long I am not sure of how the inside looks.

Also thanks for watching the videos.

Buddy

Title: Re: Old Knightkit 50 watt transmitter capacitors
Post by: uplink7 on May 09, 2018, 05:35:29 PM

Thanks for the info Buddy. Looks like Hayseed Hamfest might have what I need. They have a recap kit for the Knight T-60 that uses 700 volt caps. I'll check with them.

Title: Re: Old Knightkit 50 watt transmitter capacitors
Post by: The Radio Shop on May 11, 2018, 09:53:55 PM

Sounds like a winner. Let us know how it goes.