[Milsurplus] Dynamotor comment from a die hard user

[CL in NC]

I have a complete ARC/SCR setup with RX's and TX's, (in addition to yours in the B17F Jack) an ART13, BC375, BC191 and a Lear UT6A all running on their respective dynamotors.  With the advent of relatively inexpensive switching supplies such as ones from Meanwell, it is actually much easier to get the rigs going.  The 24 volt model supplies are usually much cheaper than the 28's, and you can run the 24's up to almost 26VDC, and why push the old girls at 28?  Of course I don't run a contest, work weak signal stuff with this gear, I use it for general operation, not as my only station.  Always fun to answer the question about the noise in the background.  I do have a TCS setup with its AC supply, plus a BC224 I am still working on a 12 dynamotor to put in it, to go with my BC191 which I have a 12V 60amp AC switcher for that, but I may be trading that for another BC375 to a fellow and his dad who restore military vehicles and have 3 jeeps under repair.  I use an AC powered BC348 with the BC375, but I do have a project BC348 with dynamotor I have not gotten to yet.

Regreasing the bearings is the number one project to take with these old motors, sometimes the grease looks and seems good, other times it looks like peanut butter.  I use Lucas high speed wheel bearing grease. A trick on the high current demand on startup with the 375 and 191 is to put a hi-watt resistor, 50 watts or more, at 1 ohm across the contactor.  Brian, KN4R told me that trick, be sure to check out his website.   Turn on the switcher supply, as soon as the motor starts to turn, turn on the rig power switch, the contactor pulls in, bypassing the 1 ohm.  Adjust the resistor for your supplies current max, my 30 amp 24 volt one will draw 24 amps across that 1 ohm on start up on the 375, but when the motor gets turning and you switch the rig on, it settles in around 5 amps or so until you go to TX.  

Charlie, W4MEC in NC