On Jan 18, 2007, at 8:57 AM, 1800 Toll Free wrote:
On Thu, 18 Jan 2007 04:22:37 -0800, R L Measures <r@...> wrote:
On Jan 17, 2007, at 4:04 PM, 1800 Toll Free wrote:
The 8877 is a waste of money, for the dollars they choose to demand
for it.
For the price of a new 8877 you can purchase an 8170 and socket
on the
used / pull market.
However, an 8877 is easier to put on 10m/11m than an 8170.
That quantifies the 'builders' vs the 'tech'.
The builder hasn't a clue as to why this part goes here, just that
someone
told him. If he starts getting oscillations or any other problem
in the
8170, he hasn't a clue as to why. It gets shipped here, fixed, and
he is
the hero.
chortle
The 8170 is harder to put most any place.
Except that with a tetrode-with-handles, where input-Q matters mot, a
continuous-coverage roller-coil tuned, grid circuit is do-able.
It has tons more gain.
However, ditch the intermediate amp you need with the triodes, and the
cost / watt ratio really goes down...
Good point. The original "Plywood Box" 8170 amp cost c. 9.5? per
watt, thanks to parts donations from my friends.
Especially when you figure in the
problems you get with paralleling multiple tubes....
2x to 4x the feedback-C is a good thing . . . . . if you need an
oscillator.
As someone else had
pointed out, good luck getting a "really" matched pair of 3CX1500?
s ...
Myself, I like to blow the 3CX1000 really hard.
For about the same amount of money you can get all the parts..
Sure, your
power xformer will cost a bit more for the anode voltage, but you
will
have a lot more life out of the tube / amp.
Good point, and, as an added FREE bonus, it's instant-on.
cheers, Mr. ______?
And since your pumping 14kw out of the 8170, and not trying to pump
7 or
more kw out of the pair of 8877s, everything is happier... Except the
technician.
7kW out / 11.6kW in with a of a pair of 8877s is walking on thin ice.
As to whom I am, We've been in contact before. I ran across you on
amps
more than a decade ago, and you, not knowing it, enabled me to
build my
first 8170 amp.
Good news. The 8170 project was the d¨¦nouement of my amp-education.
After I got everything figured out and working, I was determined to
pass along what I learned to other Hams who enjoyed building and did
not enjoy being QRMed. As I understand it, the Fuehrer of AMPS
himself, W8JI, was building an 8171.
Didn't do plywood, but... Also have a pretty kick ass
SB220 that between you, K5PRO and Dennis Ostrowski is a hot little
item as
well. Long live the TS440 :)
The SB-220 can never be kick-ass anything, but it makes a decent
driver for the 20-out 8160.
I'm also a friend of Dino's. He tried to get me to purchase the
plywood
box when it was for sale not too long ago.
Without a major mod, the Plywood Box will not do 11m/10m.
Bought a house instead.
Just call me Free..... Toll_Free lol. I have a call, but since I
flaunt
11 meter high power operation, it behooves me to keep it under wraps.
Why ? I was the first Ham on the West Coast to admit to running a
tetrode with handles, and the only people who got upset and wrote
letters to the FCC were contesters who ran tetrodes with handles and
claimed to be absolutely, positively, 100% legal.
Thanks!
ur welcome, Mr. _______ ?
--Toll_Free
The glass tubes aren't being made anymore.... At least, not
affordably.
That means it's a waste of money / time to build around them.
It's a reflection of state of the art, or hollow state, if you
will. the
russian tubes are being used because they are cheap, not because of
any
big difference in technology.
This, of course, is just ramblings from some stupid CBer :)
--Toll_Free
On Wed, 17 Jan 2007 14:28:50 -0800, alphasxsignal
<videorov@...>
wrote:
Seems to be alot of hams going to the GU84B tubes for their Big
amps over the 8877 or even the old 4-1000.
--
*Ratings are for transistors, tubes have guidelines*
Yahoo! Groups Links
R. L. Measures, AG6K, 805.386.3734
r@..., rlm@..., www.somis.org
--
*Ratings are for transistors, tubes have guidelines*
Yahoo! Groups Links
R. L. Measures, AG6K, 805.386.3734
r@..., rlm@..., www.somis.org
