Greg,
Go to the library and get the 1980 (+/-) ARRL Handbook. It
has a 160/80/40 meter amplifier project based on a single
grid driven 8833. That should give you a good start on
your project.
I suspect the broadcast transmitter that used those 833s
had a pair in parallel in the final modulated by a push-
pull pair. You will probably have an easier job making
your pair work in parallel grid driven than trying to do
a push-pull (link coupled) output unless you have the
plug in tanks from something like a BC-610.
73,
... Joe, W4TV
> -----Original Message-----
> From: amps-bounces@contesting.com
> [mailto:amps-bounces@contesting.com] On Behalf Of Greg Weinfurtner
> Sent: Tuesday, March 16, 2010 2:19 PM
> To: amps@contesting.com
> Subject: [Amps] Building 833 Amplifier. Hints and Suggestions?
>
>
> Hi all,
> I am new to the list so be kind! I went through all
> of the threads
> on amps@contesting.com concerning an amplifier using 833's
> and pretty much
> came up with very little usable information. Why 833's? Why
> do I still
> deer hunt with a muzzle loader with just iron sites? Why do
> people still
> build tube regens? Just 'cause I guess it is a challenge and
> the 833 is a
> magnificent looking tube all aglow!
>
> I was an Electronic Design Specialist for Ohio
> University for over
> 22+ years and have built a hybrid solid state 160 meter
> SSB/CW 100 watt
> transceiver (Using a pair of 6146's) from the ground up, (
> http://oak.cats.ohiou.edu/~weinfurt/160mrindex.html
> )including a 500 hz CW
> filter. Age is mid 50's and was in Tube/Solid State transition during
> college years. Yep, slip sticks to calculators to SMD's. BSS
> (Bachelor of
> Specialized Studies in Shortwave RF Engineering) is from
> 1994, so that and
> being an EDS helped keep me in the loop until I recently retired.
>
> I have all the parts to put together 160 meter single band
> amplifier. I realize that it is a low mu tube of about 35, and would
> probably not make a great grounded grid tube... but maybe at
> 160 meters a
> pair of them could reach legal limit with less than 100 watts input?
>
> I have 5 each of 833A pulls, with only 6 months of
> use. I got
> these from the engineer in charge and he said that usual pull
> time is at
> least over a year or unless some failure occurs. But, the
> owner of the
> station demanded that he do it every 6 months no matter what
> the condition
> and he kept the 'like new' ones. Yes they are old, 20 years or so.
>
> I would prefer help from someone who has actually
> used the 833 in
> some type of RF circuit. But anyone with engineering
> experience with a
> behemoth of this type knowledge would be great! I plan to
> set up a web
> page and with my progress to keep those helping informed of
> my advancement
> into the past!
>
> Characteristics for the 833A are
> at: http://oak.cats.ohiou.edu/~weinfurt/833A.pdf
>
> **************************************************************
> **********************
> Plan.
>
> 1 Two of them in parallel or Push-Pull?
>
> 2 Grid driven with a 55 ohm, 75 watt non-inductive resistor to ground.
>
> 3 Pi output network or Pi L ? Or Link coupled output?
>
> 4 Operation is CW and occasionally SSB. Bias voltage on
> Cathode developed
> across about 60v Zener to ground?
>
> 5 Power supply is capable of 3000 VDC at 1 Amp.
>
> 6 Forced air cooling up from pressurized bottom chassis to box on top
> housing tubes and output components.
>
> 7 Tubes mounted in vertical position. Heat sinks for pin connections.
>
>
>
> Greg Weinfurtner AEE BSS
> NS8O
> 40192 State Route 689
> Meigs County
> Albany, Ohio 45710
> United States of America
> _______________________________________________
> Amps mailing list
> Amps@contesting.com http://lists.contesting.com/mailman/listinfo/amps
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