[Milsurplus] TCK power supply

[Kenneth G. Gordon]

On 16 Apr 2017 at 10:20, Rob Flory wrote:

> The current rating of the 500V supply is 350mA,

Yes. I have printed that information off here for planning my supplies, thank you.

> so VR tubes would require a very heavy 
> cathode follower to run the low power stages and the screens of the finals.

I had never thought to regulate the lower power stages and the final screens. I had only 
wanted to regulate the voltage to the VFO, and probably only its screen voltage, since it is 
an ECO circuit. From the schematic, it looks as though one can make a simple connection 
to the VFO screens without drilling extra holes or doing anything non-restorable to the 
transmitter.

My TCK is in pretty bad, but restorable, condition and will take considerable work to get it in 
operation, so I had thought to run regulated voltage to the VFO only.

For one thing, I was told that most of the paint is gone, but I like painting black wrinkle 
anyway. :-)

>  For a long time I 
> wanted to try to build one but never got around to it.

Well, I need lots of "Round TUITs" to get things done here. ;-)
   
> I used a DA1F aviation dynamotor rated at 540V, 450mA, powered by a heavy duty 24V repeater 
> power supply, maybe Motorola.  In addition to providing excellent regulation, it also creates 
> rotating machine ambiance in the shack.

And I love the sound of "rotating machinery". Good on ya!

> C-135, the B+ filter in the transmitter, is 4uF at 2.0kV.  I powered my transmitter up just now and 
> my key up voltage is 2.2kV.  I recall that I unhooked that capacitor.  I don't have an antenna or 
> dummy load to run into so I was unable to check what my key-down voltage is.  

OK. Well, I will have to check all or many of the caps in my TCK-4 anyway, so I may either 
replace that one.

As I said earlier, at this point, I intend to keep my +HV at around 1800 VDC, but even so, 
2KV is, in my opinion, not enough "lee-way" above 1800 V anyway.

And thank you and Meir very much for so kindly sharing your experiences with this 
transmitter. I am really anxious to get mine in operation. The finished and operating 
transmitter will be a very impressive addition to my shack.

This will make up for that NIB TCM-2 I had many years ago, but had to give away when I left 
Missoula, Montana for good.

Although the TCK-4 transmitter is not yet here (it will arrive about April 28), I am presently 
gathering all the pieces I am going to use to build the power supplies.

I have the necessary transformers, diodes, filter capacitors, chokes, and relays, and a 
complete heavy-duty "lower" voltage supply I can use. I also have gathered all the tubes 
together and I just bought 4 ea brand new 837s. My transmitter is coming without tubes.

As I mentioned, I intend to build the power supply into a "short" Bud cabinet I have here, will 
mount that on casters, then install it under my operating bench right next to the transmitter, 
then will cable it to the transmtter from there. Total length of the cable run will be about 3 
feet.

I am also having a local machine shop build a very simple "cradle" for the transmitter to sit 
in which will have casters on it so I can roll the transmitter around more easily.

Another very interesting thing about the transmitter is that it will match output impedances 
ranging from a low of about 26 ohms to a high of over 3K ohms. It will directly match a 50 
ohm antenna, and I already have a home-brew balanced coupler which will sit right on top of 
the transmitter. My coupler is not original but will work at least as well as the original one.

I DO wish I could find one of the original balanced couplers for it, though.

Again, thanks, folks.

Ken W7EKB

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