I received so many thoughtful and valuable responses to my Alpha query I have
summarized them herein. Thanks agn for all the replys - every msg had some
nugget for me.!
1. OOOps ! I knew the tubes were 8874s but my fingers didnt and typed 8875.
2. WATCH THE GRID CURRENT- Well thats it in a nut shell. Everyone stated it
in CAPS or italics or whatever. It obviously is important. Most suggested
keeping it
ping it around 75ma for a 3 holer.
3. Multimeter switches- My switches are broken. I have gotten enough of the
amp apart to get at them and it appears they will need to be replaced. (1:
1,000,000 chance they are a Dayton flea mrkt item !!) As a side benefit
I've discovered how easy is is to get to subassemblies in this amp - avery
thoughtful and intuitive layout.
4. POWER OUT- Many people suggested tuning for max smoke while monitoring
the grid current carefully (see no. 2 !) Lowest average output was 900 watts
from someone who does not push it. Several stated that 1500 out on 160-15 was
not a prob
ot a problem. 10 was a squeaker with 1200 watts out. The point that surfaced
here is that many people drive with up to 110 watts but by watching grid
current have used the same tubes for 15 years. I also learned that some
Alphas had a damping circuit to lower drive and hence output. Recommendation -
remove it
remove it (a few resistors ).
5. WARC A few said that the 76 will run just fine on 18MHZ with no mods.
just use 15m position and tune up. Several people warned about 24 MHZ -EVEN
WITH
THE ETO MOD ! I did receive from AA4NU, the name of a gentleman who can do
a mod for 24mhz plus work on Alphas. I have no knowledge of his ability
or qualification but if you want to contact him his name ,call and adress
follow:
N4UQ, Richard Byrd, 4855 Jennifer Lane, Douglasville, GA. 30135
6. TUNE UP - Mike AA5NK sent a simple, yet pretty foolproof set of directions
1. Keepp in grid current all the time.
2. drive up to maximum of 100ma
3. reduce grid current by tuning back load, then
4. increase drive some more ..up to 100ma
5. repeat this operation until you can not drive any further
6. then lightly reduce grid with load control to vy low amt.- you should
be able to run very low grid with max smoke.
7. Thanks for the education guys ! The great responses hve given me a new level
of confidence in my purchase. Every response was useful.
8. Ill post another summary after I hear from Alpha if I get any useful info.
9. RESPONSE BREAKDOWN
DX:Tack JE1CKA/KH0AM
first QSO: N3RD
PILEUP:K0GU, N2AA, N4TQO, N2IC/0, KR2J, N6ST, N3RS, W0CP, Dave McCarthy (
sorry forgot ur call !)
SHORT SKIP:KB8NW
10. Look for me at Dayton - flea mrkt space 2119, 2mtr 145.555 +- intermod
73 Dan
___________________________________________________________
| DAN KOVATCH |
| W8CAR |
| |
| PEMS_st_dk@noeca.oecn.ohio.gov |
| REAL RADIOS GLOW IN THE DARK |
|_________________________________________________________|_
5. WARC
>From robert penneys <penneys@freezer.cns.udel.edu> Wed Apr 20 11:32:50 1994
From: robert penneys <penneys@freezer.cns.udel.edu> (robert penneys)
Subject: ped
Message-ID: <9404201032.AA29107@freezer.cns.udel.edu>
FTP'd Ped from Osaka, unzipped with latest PKunzip, said file was defective...
will wait for another copy......
Bob Penneys, WN3K Frankford Radio Club Internet: penneys@pecan.cns.udel.edu
Work: Ham Radio Outlet (Delaware) (800) 644-4476; fax (302) 322-8808
Mail at home: 12 East Mill Station Drive Newark, DE 19711 USA
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