[ARC5] VT-25 (SCR-AK-183) vs. VT-25-A (SCR-AS-183)

[Mike Morrow]

Dave wrote:

> VT25A outputs more power in this application.  More later as I can
> get to my notes and give you coil setting, loads and etc.

That will be interesting.

The change from VT-25 to VT-25-A occurred with SCR-AO-183 (Order 6120-NY-41).  SCR-A*-183 manuals for models before and AFTER show no change to Table III Typical Transmitter Plate and Bias Voltages for the VT-25-* and VT-52 tubes.  For example, what is shown for SCR-AK-183 (Order 17875-NY-39, A.R.C.) using VT-25 is identical to SCR-AS-183 (Order 2534-WF-42, Philco) using VT-25-A.

I've been unsuccessful finding data sheets for comparison of VT-25 vs. VT-25-A unless one assumes that data for VT-25 are the same as those for 10 or 10Y.  I do not know of any exact commercial equivalent to VT-25-A, unless it be...er...10 or 10Y also.

I should visually compare the VT-25 in my BC-187-A (SCR-178) to s VT-25-A from my BC-AS-230, but both are stored away from my house right now.

Mike / KK5F