MAS-80 Performance, Some thoughts and Numbers
Excerpted From An Email To KD1JV and AA1MY, plus some added comments.
It's finished, or nearly so. attached are a couple jpegs of it in the enclosure. I've had 2
QSOs with it and it seems to be working well. I tacked it loosely inside
the enclosure for bench testing and in case in case some changes need to be
made. I built it complete with the protection diode and all the sidetone and
fine tune parts.
good audio level, and sounds good
could copy W1AW in poor band condx
sidetone sounds great
receiver overloads on vy strong local signals >100W and close, no problem normally
No discernable key clicks by local hams
nice smooth tuning both main and fine tuning
rcvr stable after warm up when cover is on the enclosure.
Vy nice little rig, it's gonna be fun to play with.
Here's some numbers.
1 watt out with 12.5 volts at Q3 when keyed, expected about 2, so I dble checked
the lpf and all is ok there.
Output freq about half kc below xtal freq
Freq rock solid when keyed for 15 seconds
installed a hi pass filter for local bci and popped the final and keying
transistor (#61 Chebyschev in the handbook).
Removed filter, replaced final, no more problems No more BCI either(?)
3.482.9 - 3746.8 = 264 kc tuning range
± ~ 4 kc fine tune range
Tuned ~1.5 kc below xtal freq for ~ 600 cycle tone on received station, on both
contacts made to date.
Total current draw
Rcve only ... 17.3 ma
Xmitter keyed ... 230ma dropping as final heats up, 210ma after 15 sec
Thanx for a neat design Steve, I enjoyed building it and will give it a workout.
Seab, wanna try a sked, or 2, or 3 ...?
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