[Milsurplus] BC-221

[Kenneth G. Gordon]

On 15 Dec 2003 at 12:37, Ray Fantini wrote:

> idea what frequency you are on. the solution is a BC-221,

Excellent solution, although not particularly quick to get on a 
frequency. I ***LIKE*** the BC-221.

> schematic calls for 135 Vdc, I am assuming that it will need to be
> regulated.

Well, it SHOULD be, but isn't really too necessary. The original 
battery pack sure wasn't!

> was the stock internal power supply regulated?

If you mean an AC supply, I don't know. As I said above the 
battery pack sure wasn't.

> I was
> thinking of using a 0C3 or a 0D3 the problem being they are 105 or 150
> volt tubes, will the unit work well on 150 Vdc

Yes. No problem. I and most other people I know run ours on a 
VR-150.

> or should I use a
> voltage divider with a 105 volt tube on the end to get my 135 Vdc? or
> just operate the meter from 105 Vdc?

Either one. As I said, I and most people I know use a VR-150.

> is the little hole on the side of
> the case for the power cord to exit?

That is what I use mine for...

> and last but not least has anyone
> had any success changing the plastic window over the book, looks like
> I may have to drill out the rivets that held in the old plastic.

As someone else already mentioned, that clear, vacuum formed 
plastic used to package tools and such in is excellent for this 
purpose. I used some just recently to replace the windows in an 
ancient vernier dial.

> already stripped , cleaned and painted the case but have no idea yet on
> replacing the plastic.

As above.

BTW, the power transformer you need to use for the BC-221 
can be VERY small. There is not much current drawn from it: 
around 18 mA at max.

The BC-221 I bought recently on the Bay for $5.00 had a home-
brew power supply in it which didn't work. It was wired all 
wrong. I fixed it and the meter and it works beautifully. Very 
accurate even after all these years. Stable as a rock too. 

Good luck.

Ken Gordon W7EKB