DX-60 watts output

(1/3) > >>

N8IE:
Hello folks,
I'm new to this part of the hobby so please forgive my lack of knowledge in all things fire bottle related.  ::)

I'm working on a Heathkit DX-60 (not a DX-60a/b) and have a question of the output power I should expect from a single 6146A.

I have re-capped the radio and checked all the tubes, B+ is 308VDC, and solid (no drift)
I'm showing after tune up into a dummy load, approximately 70W on a standard watt meter.
Am I wrong in thinking this a bit high for a single 4164A?

Thanks es 73
Dan, N8IE

KB2WIG:
This may be of some help ...........  klc


http://www.amwindow.org/tech/htm/wc3kmods.htm

AB2EZ:
Yes

Sounds very high. Also, your measured plate voltage sounds very low.

The r.f. output power (if it is tuned up to maximum output) should be roughly

output power = electrical input power x 75% = B+  x  average plate current  x  75%

In typical operation (e.g., for a Johnson Ranger), with the B+ set at 550 volts and the average plate current set at .120 amps... the r.f. output power would be: 66 watts (electrical input power) x 75% ~ 50 watts.

Stu

N8IE:
Quote from: AB2EZ on April 28, 2008, 02:53:29 PM

Yes

Sounds very high. Also, your measured plate voltage sounds very low.

The r.f. output power (if it is tuned up to maximum output) should be roughly

output power = electrical input power x 75% = B+  x  average plate current  x  75%

In typical operation (e.g., for a Johnson Ranger), with the B+ set at 550 volts and the average plate current set at .120 amps... the r.f. output power would be: 66 watts (electrical input power) x 75% ~ 50 watts.

Stu




The 308VDC is the B+ for the VFO not the plate voltage, sorry for the confusion.
I'll take a voltage reading on the HV side of the PS tonight.

I notice a big difference between the voltages listed in the manuals for the DX-60 and the DX-60B.
Math tells me I may not be too far off:
Plate V = 700
Current = 150mA
Power = 105W
At 75% that figures to +/- 78W

W6REF:
Hi Dan,

I have both a DX-60 and a DX-60B, and the max power output is about the same: 60 to 65 watts into a dummy load in the CW position. These were measured using 75 and 40 xtals on the fundamental frequency, with the recommended grid drive of 2 to 3 ma.

70 watts is a bit high, but probably within tolerance of meter accuracy. Make sure your SWR is 1:1 (as it should be with a pure resistive 50-ohm load).

Good luck,

Bob
W6REF

Navigation

[0] Message Index

[#] Next page