Bruce's comments made me think about the differences between the 1/20 and the 1/12 HP motors. My experience with spinning the fan to get a motor going has been limited to 1/20 HP motors. The 1/12 HP might not be capable of being spun up by hand with a bad cap or relay. The RT set uses a 1/12 HP.

John, W9DDD

On Aug 3, 2022, at 6:32 AM, Nick England <[email protected]> wrote:

Finding a modern cap that will fit seems to be impossible.

I did find a source of NOS 125v 88-108 mfd motor start caps that seem to work fine.

1" dia x 2.4" long so they fit OK.

http://www.ebay.com/itm/141022712790

or
http://www.tedss.com/181384

Mine came quickly and were very well packed.

It turns out that these are Teletype Part 181384 as used in the M33. Also suitable as a substitute for 162074 used in 1/40 HP miniature motor M28 TD and ROTR equipment (I just cut the wire leads short and soldered to them).

They also work OK in the 1/20 HP motors in the 28KSR and 28RO. Not the correct value but I have replaced several with no issues. I haven’t tried them in the 1/12 HP motor in the 28ASR which uses yet another value cap.

The motors with bad caps would just sit and tremble until I gave the fan a quick pull and then they would spin up OK.

YMMV, no warranty, etc.

Nick

Nick England K4NYW
www.navy-radio.com

______________________________________________________________
GreenKeys mailing list
Home: http://mailman.qth.net/mailman/listinfo/greenkeys
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:[email protected]

Jordan Spencer Cunningham's GreenKeys Search Tool: https://teletype.net/gksearch

2002-to-present greenkeys archive: http://mailman.qth.net/pipermail/greenkeys/

1998-to-2001 greenkeys archive: http://mailman.qth.net/archive/greenkeys/greenkeys.html

Randy Guttery's 2001-to-2009 GreenKeys Search Tool: http://comcents.com/tty/greenkeyssearch.html

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html
Message delivered to [email protected]