Howdy,


A 6L6 immersed in a can of peanut oil is an old timey final, smells
good too.


73,
Grumpy
(Who can't get news express to work withg AIOE anymore.)

ken scharf wrote:
Fred McKenzie wrote:
In article
,
JIMMIE wrote:

I am considering an 807 as a replacement

Jimmie-

Just how simple will this transmitter be? My first novice transmitter
was built from an ARRL publication back in the 50s. The specification
was for a single 6V6, used as a crystal oscillator with output coupled
to the antenna.

I found I could get more power with a 6L6 plugged into the same socket.
Along the way to getting more power, I found that crystal current would
increase to the point where the crystal would fracture!

If you use a 807 or 1625, I hope you will have a lower power oscillator
driving it. Something like a 6AG7 would make a nice crystal oscillator,
and should have sufficient output to drive an 807.

73,
Fred
K4DII
The 6AG7 - 807 combo is a classic. E. F. Johnson sold a 50 Watt Novice
transmitter in the '50's with this tube line up (also a 5R4GY rectifier
IIRC). Other tubes that have been used as the oscillator/driver were
the 6CL6, 12BY7, 6GK6, and 5763.

On Dec 10, 9:27*pm, "
wrote:
Howdy,

A 6L6 immersed in a can of peanut oil is an old timey final, smells
good too.

73,
Grumpy
(Who can't get news express to work withg AIOE anymore.)



I tried doing that with a 4cx250 once. Never got it to work. Looking
back on it I should have mounted the base of the tube to the paint can
lid and hung it in the bucket upside down.
Hmmm, might be something fun to try this winter.

Jimmie

JIMMIE wrote:
On Dec 10, 9:27 pm, "
wrote:
Howdy,

A 6L6 immersed in a can of peanut oil is an old timey final, smells
good too.

73,
Grumpy
(Who can't get news express to work withg AIOE anymore.)



I tried doing that with a 4cx250 once. Never got it to work. Looking
back on it I should have mounted the base of the tube to the paint can
lid and hung it in the bucket upside down.
Hmmm, might be something fun to try this winter.

Jimmie
I recall an article on using a 4cx250 with water cooling. Actually it
sat upside down in a pool of water which was allowed to boil off from
the heat of the tube. Which means the tube didn't get hotter than 100
degrees C (until all the water boiled away). This is known as 'vapor
phase cooling'. Believe it or not you can cool a tube with STEAM!

JIMMIE wrote:
After years of avoiding morse code I am finally getting into it. the
ideal of operating a very simple transmitter appeals to my junkbox/
trashcan construction mentality.
I am looking for a substitue for a 6L6 that has the plate brought out
the top. I was trying to build a little Glowbug transmitter but was
having all kinds of problems neutralizing the the thing. I think I
would have better luck if I can separate the grid and plate circuits
from each other. I am considering an 807 as a replacement Suggestions
would be appreciated.

Jimmie
To Hijack an old thread...

The way tubes were numbered sometimes....
The 25L6 and 50L6 are NOT 6L6's with different heater voltages.
Actually both of these tubes are IDENTICAL with the 6W6GT except for the
heater ratings.

"ken scharf" wrote in message
.. .
To Hijack an old thread...

The way tubes were numbered sometimes....
The 25L6 and 50L6 are NOT 6L6's with different heater voltages.
Actually both of these tubes are IDENTICAL with the 6W6GT except for the
heater ratings.

Ken, isn't the 6W6 a high perveance tube, hence the relatively high
filament current? If so, it might work well in a TX with slightly
lower plate volages. I have a sleeve or two of those looking for
a project...

Pete

Tio Pedro wrote:
"ken scharf" wrote in message
.. .
To Hijack an old thread...

The way tubes were numbered sometimes....
The 25L6 and 50L6 are NOT 6L6's with different heater voltages.
Actually both of these tubes are IDENTICAL with the 6W6GT except for the
heater ratings.

Ken, isn't the 6W6 a high perveance tube, hence the relatively high
filament current? If so, it might work well in a TX with slightly
lower plate volages. I have a sleeve or two of those looking for
a project...

Pete


Based on what I found on google for 'high perveance' I guess so.
This tube has a max plate voltage rating of 330v, and a max G2 rating of
165 volts. It was used as an AF output tube in low plate voltage
radios, and in TV sets as a vertical output tube.

The 6Y6 is a similar tube, with 50ma more heater current and the same
plate dissipation rating in a larger bulb. It can handle higher plate
current than the 6W6, and it's max plate voltage and G2 rating is 200v.

I know that 50c5's and 50l6's were used in transmitter projects, so the
6W6 will work in the same circuits. The 6Y6 might bear looking into as
well.

Check out the 6CD6, 20 watts plate dissipation; max plate volts 700. The
6DQ6 is a similar tube but onlt 18 watts PD but handles 770 volts. The next
step up will be novar/duodecar compactron color TV sweep tubes which can be
expensive due to the explosion of sweep tube CB linear amps in past
years/decades.

Why not just design it around a 6146?? Easy to find--and maybe free from
another ham.

Best 73.
Russ

"ken scharf" wrote in message
.. .
JIMMIE wrote:
After years of avoiding morse code I am finally getting into it. the
ideal of operating a very simple transmitter appeals to my junkbox/
trashcan construction mentality.
I am looking for a substitue for a 6L6 that has the plate brought out
the top. I was trying to build a little Glowbug transmitter but was
having all kinds of problems neutralizing the the thing. I think I
would have better luck if I can separate the grid and plate circuits
from each other. I am considering an 807 as a replacement Suggestions
would be appreciated.

Jimmie
To Hijack an old thread...

The way tubes were numbered sometimes....
The 25L6 and 50L6 are NOT 6L6's with different heater voltages.
Actually both of these tubes are IDENTICAL with the 6W6GT except for the
heater ratings.