[R-390] R-390A Ballast tube (RT510/3TF7) replacement options document

[Jacques Fortin]

Hello Larry,

I just seen my name mentioned on the 1st page of your document for the RT510 about the 2HTF11B.
That came from the fact that when I "found" my R-390/URR, it was equipped with a 2HTF11B instead of a 3TF7.
And if you look in the Collins 1953 manual for the R-390/URR or in the TM11-856, figure TM 856-10 in both cases, it can be seen on the picture that the IF chassis bear the number *HTF11B for the RT510.

To "save" those ballast tubes, I have adapted the socket to use a 12BY7 in my R-390 and R-390As.
No real difference, as reported by many others...

73, Jacques, VE2JFE in Montreal