[Amps] GS35B Amps Common Problem / few more comments

[Jim W7RY]

Right. That is why the 3cx800 works so well here.


3cx800 is also a GREAT tube.

I use both the 8877 and a pair of 3cx800s in my homebrew amplifiers.

Sent from my wireless communicator
73 Jim W7RY

3cx800s are 25 years old. 1500 watts out in RTTY contesting.

Narry an issue. Still full output with 40 to 45 watts drive.





On Wed, Nov 6, 2019, 4:10 PM BILL KENNAMER <k5fuv at prodigy.net> wrote:

> Doubling the voltage. The 76 voltage is too low for the 8877.
> 73
> Bill K5FUV
>
>
> Sent from Yahoo Mail for iPad
>
>
> On Wednesday, November 6, 2019, 3:48 PM, Steve London <n2icarrl at gmail.com>
> wrote:
>
> Okay....I'll be stupid....
>
> Besides the filament voltage and socket, what else would it take to
> convert
> something like a 3 tube Alpha 76 to a single 8877 ? Seems like the output
> Z is
> in the right ballpark.
>
> 73,
> Steve, N2IC
>
> On 11/06/2019 02:26 PM, Jim wrote:
> > Agreed! 8877 is one the the BEST tubes for ham radio.
> >
> > LOTS of them out there and available. Hams bought many of them for
> spares that
> > never got used; Because the 8877 was such a robust tube. Most 8877 tubes
> got
> > babied... Except for contesting... But there is testimonial from K3LR's
> large
> > and busy contest station below. So even in a contesting environment, the
> 8877
> > goes STRONG!
> >
> > 8877/3CX1500A7 hard to beat!
> >
> > Thanks
> > 73
> > Jim W7RY
> >
> > On 11/5/2019 8:34 PM, Tim Duffy wrote:
> >> Hello Jim,
> >>
> >> I agree - the 8877 - 3CX1500 is a VERY good Ham Radio tube. I have
> several in
> >> service here at K3LR that are 30 years plus years old.
> >> 18 amplifiers here using 8877s that make 1500 watts output RTTY with
> high TX
> >> duty cycle - no problem - all the way to 220 MHz!
> >>
> >> The 8877 is an excellent engineered tube for amateur radio - easy to
> build
> >> amplifiers with the 3CX1500A7.
> >>
> >> 73
> >> Tim K3LR
> >>
> >> -----Original Message-----
> >> From: Amps [mailto:amps-bounces at contesting.com] On Behalf Of MU 4CX250B
> >> Sent: Tuesday, November 5, 2019 9:12 PM
> >> To: Carl
> >> Cc: amps at contesting.com
> >> Subject: Re: [Amps] GS35B Amps Common Problem / few more comments
> >>
> >> You may be a bit harsh, Carl!  I’ve lost two 8877s  in the past half
> >> century or so, and it was my fault both times. The first was when I
> >> stupidly let the filament voltage drop way below specs, and the second
> >> was when the blower on my Alpha 9500 failed and I didn’t notice for
> >> two weeks. My workhorse homebrew amp, built in the 1970s, has an Eimac
> >> 8877 with a 1978 date code. Still full output, 4300V on the anode.
> >> 73,
> >> Jim w8zr
> >>
> >> Sent from my iPhone
> >>
> >>> The 8877 is a fragile short life wannabee befitting an oxide cathode
> tube
> >>>
> >>>
> >>> Carl
> >>>
> >>>
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