A Radio forum. RadioBanter

If this is your first visit, be sure to check out the FAQ by clicking the link above. You may have to register before you can post: click the register link above to proceed. To start viewing messages, select the forum that you want to visit from the selection below.

Go Back   Home » RadioBanter forum » rec.radio.amateur » Homebrew
Site Map Home Register Authors List Search Today's Posts Mark Forums Read Web Partners

My vacuum tube homebrew transmitter



 
 
Thread Tools Display Modes
  #1  
Old August 24th 07, 01:26 AM posted to rec.radio.amateur.homebrew
Straydog
external usenet poster
 
Posts: 76
Default My vacuum tube homebrew transmitter


FYI, FWIW...

As I recently became retired my interests have evolved towards building
homebrew tube gear. Reasons: i) simplicity in circuitry, ii) comparatively
large tubes & sockets make soldering easier, iii) accidental slip of the
test prod might not kill a tube but might a transistor, iv) yeah, I like to
see those filaments glow, too, v) can still get those tubes but some
transistors you can't find anywhere, v) throw-away technology (boards) is
bad ecology...give me discrete devices any day, and vi) with high power heat
sinks, silicon compound for conduction of heat (if it gets on your
fingers, its hard to get it off) is needed and that damned metal can
getdamned hot.

I've been building a tube SSB transmitter for about 1-2 years now (parts of
it can be seen at http://www.panix.com/~asd) and ends up with a pair of 813s
in grounded-grid, driven by a single 811a in G-G, lots of home brew antenna
tuners, and Icom 707 for the moment SSB transciever.

The homebrew SSB exciter lineup is not yet pictured, but at its current
stage of construction is almost ready to go on the air. Generate DSB at 2
mHz with 6AL5 balanced modulator, upconvert by mixing with 7 mHz to 9 mHz
(6BE6), use McCoy 9 mHz crystal filter (somebody gave it to me 25 years
ago) to shave off the desired sideband, mix (6SA7) with 5 mHz local
oscilator (by doubled 2.5 mHz from old war surplus Collins 70H3 VFO [from
Fair Radio Sales when they had them, they ran out years ago]) to get 4 mHz
(75 meters, my favorite ragchew band) which the scope shows to be about 5-10
mv, and goes into two 6C4s (triodes, grounded cathode) and then into
a 6AG7 & 6146. I am at the point where I need to make a RF transformer
to take the output of the 6146 to drive two more 6146s in parallel to get
the ten watts I need to drive the G-G 811a. Yes, if I could optimize
everything better, I could use less tubes. But, I preferred to make
modules (lots of stages are built inside of old computer power supply
cabinets (they are about 6x6x4 or so, and nice to work with, cheap at
hamfests at $1 each or so). All the gear is full of those old D'arsonval
"Frankenstein"-type (real) meters (not this LED crap), so I can keep
monitoring practically all the voltages on anything. Its not very pretty to
look at, but its a whole lot easier to work on than any of that new gear out
that surely has thousands of transistors and hundreds of chips (?).

I chose the 813s and 811 and GG amps because both the 813 and 811 don't
really need cooling fans (I hate blower/fan noises) and grounded-grid amps
are notoriously stable (no neutralization headaches), and they are pretty
cheap. I have several 813s, some made in China; one of the Chinese 813s had
a filament that opened up on me all by itself after very little use (don't
know if that is THEIR quality control or just a statistical fluke, but I
thought I'd pass that along to y'all). I also manage filament warmup and
cooldown on the 813s with a variac (up and down over abut 5-10 seconds), but
not on the 811 amp. Been using the 813s + 811 for over a year (using the
Icom 707 as driver) and just love how nice and quiet it is without
fans/blower noise.

Almost all of my old rigs are also pictured on that URL, and a couple of
pictures of my "secret lab" out in the garage (heated with a space heater in
the winter, cooled with a small airconditioner in the summer).

I started as a novice in 1959. Had a Knight kit T-50 and Knight R-100
receiver, later got a DX-40. Mostly liked to ragchew with locals on ten
meters AM at the time. Lots of find memories. Lots of SWLing.

I'd like to hear from other homebrewers, HFers, ragchewers and learn if ther
are any 75 meter nets for homebrewers/tubers/etc. I look at all this new
gear coming out (for thousands of dollars) with hundreds of buttons, knobs,
and "thangs" on them, and big thick manuals you have to read to figure out
how to push the buttons (once, press twice, press and hold?, press and hold
one, then turn on the power switch? Etc? Secret "reboot" buttons hidden
somewhere. Built in DRM, DCMA, spyware? Too?). What happened to
old-fashioned skill? 50 years ago guys worked the world with a crystal and a
single 6L6 and straight key. Now, they are all couch potatoes in front of a
black box that looks like its from outer space. ;-)

I figure I'm within a week or two of getting the homebrew SSB exciter
actually on the air. I've been testing the outputs of various stages either
using the Icom 707 as general coverage receiver, one or two oscilloscopes to
check generated signals, etc. Still have a lot of tweaking to do. Its been a
ton of work, debugging and rebuilding when something doesn't work, but its
also been an incomparable sense of accomplishment, too, when I get a stage
to work and make progress (four steps forward, three steps backwards). Its
also nice to have some test equipment (generators, meters, a good
oscilloscope [had a Tektronix 922 that gave up and I tossed, then a heathkit
which had a dead vertical amp that I fixed, and a BK-1420? very nice but now
the horizontal sweep died but vertical amp still good, so I can probe at
least for RF which gives me a vertical line [keeping the test equipment
going is also a problem], and all of that stuff is also 30+ years old).

After that, I plan to build a tube receiver and maybe even build a crystal
lattice filter, and try to build a stable VFO.

Art, W4PON
Member, QCWA
~99.9% of my time with soldering iron & screwdriver, 0.1% of my time in
ragchewing.


  #2  
Old August 24th 07, 02:17 AM posted to rec.radio.amateur.homebrew
Scott
external usenet poster
 
Posts: 162
Default My vacuum tube homebrew transmitter

Might not kill a tube, but it could kill a builder! Be careful!!

Scott
N0EDV

Straydog wrote:

FYI, FWIW...

As I recently became retired my interests have evolved towards building
homebrew tube gear. Reasons:



iii) accidental slip of the
test prod might not kill a tube but might a transistor,

  #3  
Old August 24th 07, 10:24 AM posted to rec.radio.amateur.homebrew
George McLeod
external usenet poster
 
Posts: 4
Default My vacuum tube homebrew transmitter

It is great to know that I am not the last dinosaur left on the planet.

Although my call goes back to the 1950's when I was very active with all
home brew equipment, there has been a period of inactivity with family and
other hobby interests (such as aviation) and I have kept amateur radio as my
real retirement activity.
With commercially manufactured equipment now mandated here for foundation
licence applicants my greatest fear is that we will lose our greatest
priviledge of being able to design and build our own transmitting equipment.
My first SSB transmitter was, of course, all valve. It started at 483Khz
with a phasing system followed by two half lattice crystal filter sections.
Output started as a 6146 and then grew to 4x811A's in parallel. One of the
real problems was getting the VFO really stable and the best I came up with
used the worm drive capacitor out of one of those TU6 tuning boxes with the
tuned circuits connected remotely via coax lines to the oscillator stage
which was on the main chassis.
All a long time ago but I still believe that such experiments were a good
way to learn and am also of the opinion that the newcomers who simply
purchase a commercial rig are missing out on a lot of the basic fun that we
had when a piece of junk disposals equipment could be transformed into
something useful.

Good luck to you Art, hope you continue to enjoy the hobby

George
"Straydog" wrote in message
.com...

FYI, FWIW...

As I recently became retired my interests have evolved towards building
homebrew tube gear. Reasons: i) simplicity in circuitry, ii) comparatively
large tubes & sockets make soldering easier, iii) accidental slip of the
test prod might not kill a tube but might a transistor, iv) yeah, I like

to
see those filaments glow, too, v) can still get those tubes but some
transistors you can't find anywhere, v) throw-away technology (boards) is
bad ecology...give me discrete devices any day, and vi) with high power

heat
sinks, silicon compound for conduction of heat (if it gets on your
fingers, its hard to get it off) is needed and that damned metal can
getdamned hot.

I've been building a tube SSB transmitter for about 1-2 years now (parts

of
it can be seen at http://www.panix.com/~asd) and ends up with a pair of

813s
in grounded-grid, driven by a single 811a in G-G, lots of home brew

antenna
tuners, and Icom 707 for the moment SSB transciever.

The homebrew SSB exciter lineup is not yet pictured, but at its current
stage of construction is almost ready to go on the air. Generate DSB at 2
mHz with 6AL5 balanced modulator, upconvert by mixing with 7 mHz to 9 mHz
(6BE6), use McCoy 9 mHz crystal filter (somebody gave it to me 25 years
ago) to shave off the desired sideband, mix (6SA7) with 5 mHz local
oscilator (by doubled 2.5 mHz from old war surplus Collins 70H3 VFO [from
Fair Radio Sales when they had them, they ran out years ago]) to get 4 mHz
(75 meters, my favorite ragchew band) which the scope shows to be about

5-10
mv, and goes into two 6C4s (triodes, grounded cathode) and then into
a 6AG7 & 6146. I am at the point where I need to make a RF transformer
to take the output of the 6146 to drive two more 6146s in parallel to get
the ten watts I need to drive the G-G 811a. Yes, if I could optimize
everything better, I could use less tubes. But, I preferred to make
modules (lots of stages are built inside of old computer power supply
cabinets (they are about 6x6x4 or so, and nice to work with, cheap at
hamfests at $1 each or so). All the gear is full of those old D'arsonval
"Frankenstein"-type (real) meters (not this LED crap), so I can keep
monitoring practically all the voltages on anything. Its not very pretty

to
look at, but its a whole lot easier to work on than any of that new gear

out
that surely has thousands of transistors and hundreds of chips (?).

I chose the 813s and 811 and GG amps because both the 813 and 811 don't
really need cooling fans (I hate blower/fan noises) and grounded-grid amps
are notoriously stable (no neutralization headaches), and they are pretty
cheap. I have several 813s, some made in China; one of the Chinese 813s

had
a filament that opened up on me all by itself after very little use (don't
know if that is THEIR quality control or just a statistical fluke, but I
thought I'd pass that along to y'all). I also manage filament warmup and
cooldown on the 813s with a variac (up and down over abut 5-10 seconds),

but
not on the 811 amp. Been using the 813s + 811 for over a year (using the
Icom 707 as driver) and just love how nice and quiet it is without
fans/blower noise.

Almost all of my old rigs are also pictured on that URL, and a couple of
pictures of my "secret lab" out in the garage (heated with a space heater

in
the winter, cooled with a small airconditioner in the summer).

I started as a novice in 1959. Had a Knight kit T-50 and Knight R-100
receiver, later got a DX-40. Mostly liked to ragchew with locals on ten
meters AM at the time. Lots of find memories. Lots of SWLing.

I'd like to hear from other homebrewers, HFers, ragchewers and learn if

ther
are any 75 meter nets for homebrewers/tubers/etc. I look at all this new
gear coming out (for thousands of dollars) with hundreds of buttons,

knobs,
and "thangs" on them, and big thick manuals you have to read to figure out
how to push the buttons (once, press twice, press and hold?, press and

hold
one, then turn on the power switch? Etc? Secret "reboot" buttons hidden
somewhere. Built in DRM, DCMA, spyware? Too?). What happened to
old-fashioned skill? 50 years ago guys worked the world with a crystal and

a
single 6L6 and straight key. Now, they are all couch potatoes in front of

a
black box that looks like its from outer space. ;-)

I figure I'm within a week or two of getting the homebrew SSB exciter
actually on the air. I've been testing the outputs of various stages

either
using the Icom 707 as general coverage receiver, one or two oscilloscopes

to
check generated signals, etc. Still have a lot of tweaking to do. Its been

a
ton of work, debugging and rebuilding when something doesn't work, but its
also been an incomparable sense of accomplishment, too, when I get a stage
to work and make progress (four steps forward, three steps backwards). Its
also nice to have some test equipment (generators, meters, a good
oscilloscope [had a Tektronix 922 that gave up and I tossed, then a

heathkit
which had a dead vertical amp that I fixed, and a BK-1420? very nice but

now
the horizontal sweep died but vertical amp still good, so I can probe at
least for RF which gives me a vertical line [keeping the test equipment
going is also a problem], and all of that stuff is also 30+ years old).

After that, I plan to build a tube receiver and maybe even build a crystal
lattice filter, and try to build a stable VFO.

Art, W4PON
Member, QCWA
~99.9% of my time with soldering iron & screwdriver, 0.1% of my time in
ragchewing.





  #4  
Old August 24th 07, 10:53 AM posted to rec.radio.amateur.homebrew
Highland Ham
external usenet poster
 
Posts: 250
Default My vacuum tube homebrew transmitter

What happened to old-fashioned skill? 50 years ago guys worked the world with a crystal
and a single 6L6 and straight key. Now, they are all couch potatoes in front of a
black box that looks like its from outer space. ;-)

==============================
50 years ago the bands were sooooo quiet (relatively speaking) that you
didn't need today's sophistication
Although even today ,by using QRP equipment ....and Morse
telegraphy.........simple gear can still give a lot of enjoyment, but
in 20 - 30 years time ,how many hams will then still be using Morse code?
But as far as 'local ragchew' is concerned , I agree with you ,simple
homebrew gear will still do the trick .

Frank GM0CSZ / KN6WH north of Scotland
  #5  
Old August 24th 07, 11:17 AM posted to rec.radio.amateur.homebrew
Highland Ham
external usenet poster
 
Posts: 250
Default My vacuum tube homebrew transmitter

With commercially manufactured equipment now mandated here for foundation
licence applicants my greatest fear is that we will lose our greatest
priviledge of being able to design and build our own transmitting equipment.
My first SSB transmitter was, of course, all valve. It started at 483Khz
with a phasing system followed by two half lattice crystal filter sections.
Output started as a 6146 and then grew to 4x811A's in parallel. One of the
real problems was getting the VFO really stable and the best I came up with
used the worm drive capacitor out of one of those TU6 tuning boxes with the
tuned circuits connected remotely via coax lines to the oscillator stage
which was on the main chassis.
All a long time ago but I still believe that such experiments were a good
way to learn and am also of the opinion that the newcomers who simply
purchase a commercial rig are missing out on a lot of the basic fun that we
had when a piece of junk disposals equipment could be transformed into
something useful.

=============================================
Firstly , Foundation Licensees in the UK are permitted to use
self-constructed transmitting equipment from an 'approved kit' ,
whatever that 'approved' means.

The younger generation(s) are no longer interested in our hobby for all
the well known reasons, Internet- Mobile Phones - Sat TV - iPod etc.
Their first priority is 'socialising' and a 'nerd' sitting in a shack
soldering and using test equipment is NOT socialising.
Moreover ,homebrew equipment is NOT necessarily cheaper than
off-the-shelf stuff (with the exception of very basic equipment and
peripherals).

Being involved in assisting people to get a Ham licence , most if not
all recruits are retired or are about to retire.
We now live in 2007 and beyond ............that's the reality .

However ,being an old fogy myself .....I still do enjoy home-brewing.


Frank GM0CSZ / KN6WH north of Scotland
  #6  
Old August 24th 07, 06:14 PM posted to rec.radio.amateur.homebrew
Tim Shoppa
external usenet poster
 
Posts: 263
Default My vacuum tube homebrew transmitter

On Aug 23, 9:17 pm, Scott wrote:
Might not kill a tube, but it could kill a builder! Be careful!!


Oh, come on. How could anyone have not touched a low-kilovolt B+ and
call himself a ham?

We've all touched a kilovolt or two, probably as young kids, and we're
all perfectly normal!

Tim.


  #7  
Old August 24th 07, 11:29 PM posted to rec.radio.amateur.homebrew
Scott
external usenet poster
 
Posts: 162
Default My vacuum tube homebrew transmitter

Well, all humor aside, I stand by my original answer to BE CAREFUL.
True, a KV might not kill you, but if you start out being careless, when
you progress up to tubes like a 4-1000A, the B+ will most certainly kill
you. The pile of ashes on the floor will be proof enough

Again, humor aside, I pride myself on NOT having hit a KV...that takes
more skill than hitting it

Scott
N0EDV

Tim Shoppa wrote:

On Aug 23, 9:17 pm, Scott wrote:

Might not kill a tube, but it could kill a builder! Be careful!!



Oh, come on. How could anyone have not touched a low-kilovolt B+ and
call himself a ham?

We've all touched a kilovolt or two, probably as young kids, and we're
all perfectly normal!

Tim.



--
Scott
http://corbenflyer.tripod.com/
Gotta Fly or Gonna Die
Building RV-4 (Super Slow Build Version)
  #8  
Old August 25th 07, 04:42 AM posted to rec.radio.amateur.homebrew
Straydog
external usenet poster
 
Posts: 76
Default My vacuum tube homebrew transmitter


See quoted material at end.

When I was a kid, I and the guys I hung out with were always playing with
high voltage. We all built Tesla coils (12-15" sparks), played with Model
T Ford spark coils (2" sparks), neon sign transformers that weighed 50
pounds and put out 15,000 volts at 30 to 50 milliamps, and
Frankenstein-type "jacobs ladders." We made sparks. We made arcs. We made
noise. We made smoke. We blew fuses. One more thing we all made was an old
fashioned "repulsion coil" (coat hangers, wire, copper or alluminum ring
that would jump up a foot when you threw the switch). We all made crystal
sets, too. Made one transistor radios, too. Built Knight kits and
heathkits.

Yes, you do NOT want to be a _klutz_ and goof off like we did. Yes, you do
not want to play "electric chair" with yourself, and yes, its a very good
idea when working with lethal voltage to keep one hand in your pocket when
anything is "live". Repeat: if you are a klutz, or accident-prone, then do
not mess around with this stuff.

Beyond that, yes, I got a few shocks. I even felt current from a 12 volt
car battery (moist hands, large metal electrods, and use one hand on each,
squeeze tight, I felt a mini-tingle). Got a nast RF burn by accidentally
touching the plate cap of a 6146 with 50 watts of 10 meters carrier. It
hurts and burnt flesh (part of my thumb) stinks like hell. I got a few
more shocks, all minor, and whenever I'm around serious voltage and
power, I definitely look twice at everything.

Most scandalous shock: Outside the house. Rainstorm coming and lightning
and thunder comes 10 seconds later, means its all about two miles away,
and I'm playing with the feedline on a 75 meter dipole with my hands, and
then the next flash of light from the lightning and--dang it--I felt that
"needle" in my hand from a pulse of electricity. Hmmmm...better get inside
the house. So, next time you are listening on HF and when the lightning
and thunder are close, and your S-meter needle is bouncing all the way to
the top, you can be thiking about 100-200 volt pulses, eh? Anyway, just
think about Ben Franklin who was flying his kites in the rain (in my case,
I was dry and the rain wasn't falling yet where I was).

W4PON
===== no change to below, included for reference and context =====

On Fri, 24 Aug 2007, Scott wrote:

Might not kill a tube, but it could kill a builder! Be careful!!

Scott
N0EDV

Straydog wrote:

FYI, FWIW...

As I recently became retired my interests have evolved towards building
homebrew tube gear. Reasons:



iii) accidental slip of the
test prod might not kill a tube but might a transistor,

  #9  
Old August 25th 07, 04:51 AM posted to rec.radio.amateur.homebrew
Straydog
external usenet poster
 
Posts: 76
Default My vacuum tube homebrew transmitter



On Fri, 24 Aug 2007, George McLeod wrote:

It is great to know that I am not the last dinosaur left on the planet.


Jeeze, what is it, you and me against the world? ;-)

Although my call goes back to the 1950's when I was very active with all
home brew equipment, there has been a period of inactivity with family and
other hobby interests (such as aviation) and I have kept amateur radio as my
real retirement activity.


Yeah, I go to the local QCWA monthly lunches and what does everyone talk
about? Not ham radio (but everyone has a ricebox), but their medical
problems. Lots of them.

With commercially manufactured equipment now mandated here for foundation
licence applicants my greatest fear is that we will lose our greatest
priviledge of being able to design and build our own transmitting equipment.


That is really sad. So, along with Microsoft as ultimate software
robber-barron, we all become slaves to "commercial" interests.

My first SSB transmitter was, of course, all valve. It started at 483Khz
with a phasing system followed by two half lattice crystal filter sections.
Output started as a 6146 and then grew to 4x811A's in parallel. One of the
real problems was getting the VFO really stable and the best I came up with
used the worm drive capacitor out of one of those TU6 tuning boxes with the
tuned circuits connected remotely via coax lines to the oscillator stage
which was on the main chassis.


Soon I will approach this problem. I may end up with a bank of crystals
with a small variable capacitor to "warp" the crystal frequency. Free
running oscillators are very hard to stabilize. The other option is to
just leave them turned on, 24/7, so they are always warmed up.

All a long time ago but I still believe that such experiments were a good
way to learn and am also of the opinion that the newcomers who simply
purchase a commercial rig are missing out on a lot of the basic fun that we
had when a piece of junk disposals equipment could be transformed into
something useful.


I agree 100%. I grew up in the 1950s and we had Popular Science, Popular
Mechanics, and Mechanics Illustrated magazines. All kinds of
do-it-yourself projects, diagrams, how-tos, everything. I loved it.

Today, its all "appliance operator" stuff in a throw away economy. It
makes no sense to me.

Good luck to you Art, hope you continue to enjoy the hobby


Thanks for all the good words.

One more thing: "Long live dinosaurs!"

W4PON
===== no change to below, included for reference and context =====
George
"Straydog" wrote in message
.com...

FYI, FWIW...

As I recently became retired my interests have evolved towards building
homebrew tube gear. Reasons: i) simplicity in circuitry, ii) comparatively
large tubes & sockets make soldering easier, iii) accidental slip of the
test prod might not kill a tube but might a transistor, iv) yeah, I like

to
see those filaments glow, too, v) can still get those tubes but some
transistors you can't find anywhere, v) throw-away technology (boards) is
bad ecology...give me discrete devices any day, and vi) with high power

heat
sinks, silicon compound for conduction of heat (if it gets on your
fingers, its hard to get it off) is needed and that damned metal can
getdamned hot.

I've been building a tube SSB transmitter for about 1-2 years now (parts

of
it can be seen at http://www.panix.com/~asd) and ends up with a pair of

813s
in grounded-grid, driven by a single 811a in G-G, lots of home brew

antenna
tuners, and Icom 707 for the moment SSB transciever.

The homebrew SSB exciter lineup is not yet pictured, but at its current
stage of construction is almost ready to go on the air. Generate DSB at 2
mHz with 6AL5 balanced modulator, upconvert by mixing with 7 mHz to 9 mHz
(6BE6), use McCoy 9 mHz crystal filter (somebody gave it to me 25 years
ago) to shave off the desired sideband, mix (6SA7) with 5 mHz local
oscilator (by doubled 2.5 mHz from old war surplus Collins 70H3 VFO [from
Fair Radio Sales when they had them, they ran out years ago]) to get 4 mHz
(75 meters, my favorite ragchew band) which the scope shows to be about

5-10
mv, and goes into two 6C4s (triodes, grounded cathode) and then into
a 6AG7 & 6146. I am at the point where I need to make a RF transformer
to take the output of the 6146 to drive two more 6146s in parallel to get
the ten watts I need to drive the G-G 811a. Yes, if I could optimize
everything better, I could use less tubes. But, I preferred to make
modules (lots of stages are built inside of old computer power supply
cabinets (they are about 6x6x4 or so, and nice to work with, cheap at
hamfests at $1 each or so). All the gear is full of those old D'arsonval
"Frankenstein"-type (real) meters (not this LED crap), so I can keep
monitoring practically all the voltages on anything. Its not very pretty

to
look at, but its a whole lot easier to work on than any of that new gear

out
that surely has thousands of transistors and hundreds of chips (?).

I chose the 813s and 811 and GG amps because both the 813 and 811 don't
really need cooling fans (I hate blower/fan noises) and grounded-grid amps
are notoriously stable (no neutralization headaches), and they are pretty
cheap. I have several 813s, some made in China; one of the Chinese 813s

had
a filament that opened up on me all by itself after very little use (don't
know if that is THEIR quality control or just a statistical fluke, but I
thought I'd pass that along to y'all). I also manage filament warmup and
cooldown on the 813s with a variac (up and down over abut 5-10 seconds),

but
not on the 811 amp. Been using the 813s + 811 for over a year (using the
Icom 707 as driver) and just love how nice and quiet it is without
fans/blower noise.

Almost all of my old rigs are also pictured on that URL, and a couple of
pictures of my "secret lab" out in the garage (heated with a space heater

in
the winter, cooled with a small airconditioner in the summer).

I started as a novice in 1959. Had a Knight kit T-50 and Knight R-100
receiver, later got a DX-40. Mostly liked to ragchew with locals on ten
meters AM at the time. Lots of find memories. Lots of SWLing.

I'd like to hear from other homebrewers, HFers, ragchewers and learn if

ther
are any 75 meter nets for homebrewers/tubers/etc. I look at all this new
gear coming out (for thousands of dollars) with hundreds of buttons,

knobs,
and "thangs" on them, and big thick manuals you have to read to figure out
how to push the buttons (once, press twice, press and hold?, press and

hold
one, then turn on the power switch? Etc? Secret "reboot" buttons hidden
somewhere. Built in DRM, DCMA, spyware? Too?). What happened to
old-fashioned skill? 50 years ago guys worked the world with a crystal and

a
single 6L6 and straight key. Now, they are all couch potatoes in front of

a
black box that looks like its from outer space. ;-)

I figure I'm within a week or two of getting the homebrew SSB exciter
actually on the air. I've been testing the outputs of various stages

either
using the Icom 707 as general coverage receiver, one or two oscilloscopes

to
check generated signals, etc. Still have a lot of tweaking to do. Its been

a
ton of work, debugging and rebuilding when something doesn't work, but its
also been an incomparable sense of accomplishment, too, when I get a stage
to work and make progress (four steps forward, three steps backwards). Its
also nice to have some test equipment (generators, meters, a good
oscilloscope [had a Tektronix 922 that gave up and I tossed, then a

heathkit
which had a dead vertical amp that I fixed, and a BK-1420? very nice but

now
the horizontal sweep died but vertical amp still good, so I can probe at
least for RF which gives me a vertical line [keeping the test equipment
going is also a problem], and all of that stuff is also 30+ years old).

After that, I plan to build a tube receiver and maybe even build a crystal
lattice filter, and try to build a stable VFO.

Art, W4PON
Member, QCWA
~99.9% of my time with soldering iron & screwdriver, 0.1% of my time in
ragchewing.






  #10  
Old August 25th 07, 04:57 AM posted to rec.radio.amateur.homebrew
Straydog
external usenet poster
 
Posts: 76
Default My vacuum tube homebrew transmitter



On Fri, 24 Aug 2007, Highland Ham wrote:

What happened to old-fashioned skill? 50 years ago guys worked the world
with a crystal and a single 6L6 and straight key. Now, they are all couch
potatoes in front of a
black box that looks like its from outer space. ;-)

==============================
50 years ago the bands were sooooo quiet (relatively speaking) that you
didn't need today's sophistication


I am retired out in the country (nearest town is 7 miles away, nearest
traffic light is 2.2 miles away). here, now, in the summertime, my
background static noise on 75 meters, believe it or not, is usually about
S 1 to S3. Only when we have thunderstorms does it get up to S 9 or more.
Yes. Believe it or not. A guy I ragchew with on 75 meters lives in the
city. His noise is never less than S8 and quite often 20-40 db over S 9,
and he can't find the source.

Although even today ,by using QRP equipment ....and Morse
telegraphy.........simple gear can still give a lot of enjoyment, but
in 20 - 30 years time ,how many hams will then still be using Morse code?


It will be like slide rules and logarithms: forgotten. If teh kids can't
find the answers on the internet, then the project just will not be done.
And, they are still trying to figure out how the Egyptians built the
pyramids.

But as far as 'local ragchew' is concerned , I agree with you ,simple
homebrew gear will still do the trick .


Yep.

Frank GM0CSZ / KN6WH north of Scotland


Good luck with Gordon Brown!!!

 




Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

vB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
UPLC on BPL: ignore armchair amateurs who still use vacuum tube transmitter Steve Robeson, K4CAP Policy 6 June 28th 04 06:24 AM
FA: Homebrew tube transmitter on Ebay GS Boatanchors 0 February 10th 04 04:47 AM
FA: Homebrew tube transmitter on Ebay GS Swap 0 February 10th 04 04:47 AM
Vacuum Tube VFO Fred Homebrew 0 July 7th 03 11:48 PM


All times are GMT +1. The time now is 05:34 AM.


Powered by vBulletin® Version 3.6.4
Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.
Copyright 2004-2014 RadioBanter.
The comments are property of their posters.