[Central-Electronics] CE-20A, BC458, HQ-145 On the air!

[k6jek]

The CE-458 will stabilize if you leave it plugged in because the filaments are on all the time. However, from a cold start it takes hours to settle down. I measured 4 Hz/minute after 1:15.  While the other guy is yammering away for ten minutes you've moved 40 Hz.

The 20A also drifts  but not as much, courtesy of the 9 MHz oscillator. Even with a rock solid VFO you'll still get some drift.  After 1:30 it was drifting about -8Hz/10 minutes, not so bad actually. Total drift after 90 minutes was -238 Hz. That's with an external, DDS VFO that didn't move an iota.

Cold start. Temperature controlled room, 68 degrees.

A small fan blowing in the side towards the crystal seems to tame the drift of the 20A. I only ran this experiment once so I'm not dead certain but after 90 minutes the drift rate was about -2 Hz/minute with a total drift from cold start of -75 Hz and -54 of that was in the first thirty minutes.

I have the huff & puff parts but haven't done anything with them. I run with the 20A, a 220 V fan on 120V so it's quiet blowing in the left side lower front vent and a DDS VFO . I don't tell anyone about the DDS VFO.

Actually, I use the CE 458 sometimes but only if I remember to plug it in several hours before I want to use it.

Jon





On Mar 21, 2012, at 2:38 PM, Ron.K3PID wrote:

> I finished up the BC-458 conversion ( minus the X-Lock for now) and since I run a local slow speed net on Tuesday nite I warmed them up for an hour and ran the net with teh "vintage" station consisting of my restored CE-20A, restored HQ-145 ( I love the crystal filter) and the BC-458 VFO. A lot of fun and good feedback.  I had forgotten about the distraction of the clacking keying relay! I'll have to put on the headphones next time....  Great Fun! I haven't had that much fun since 1961...
> 
> Ron H. K3PID
> 
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