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Old March 5th 07, 02:09 AM posted to rec.radio.amateur.moderated
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Default Tube equipment question


"Ivor Jones" wrote in message
...
"Mike Coslo" wrote in message
6
wrote:


[snip]


That brings up a related issue. Lots of Hams today are
restricted to one antenna, yet they would like all band
operation. I think it would be a great idea for a
manufacturer to have a transciever that included a tuner
right in the rig itself.

- 73 de Mike KB3EIA -


They do exist, although being primarily interested in VHF/UHF operation
(we only recently had the morse requirement for HF dropped over here in
the UK, but that's another topic..!!) I've had little experience of them.


My main HF rig and my husband's main HF rig both have built in tuners. Both
work pretty well. However they do not have the range of outboard tuners.

I do remember vividly using a Drake commercial HF transceiver (I think it
came out of a ship's radio room) back in the late 80's at a special event
station that had this feature, you could operate on any band without any
form of tuning at all, although of course how much power would get out on
a really bad antenna is debatable ;-)


A lot of commericial and military equipment have built in tuners with quite
significant tuning ranges. Of course this comes at a price so amateur gear
doesn't have as much range in their tuning capacity on the built in tuners.

Of course if you've enough money, there are those antennas that tune
themselves. A friend has a 3-element beam that is computer controlled; as
you tune across the bands, the elements automatically adjust themselves to
the correct length..! I don't recall the make/model, but it is of American
origin, does anyone know of it..?

73 Ivor G6URP


I think it is called the SteppIR. Too rich for my pocket book.

Dee, N8UZE



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Old March 5th 07, 02:10 AM posted to rec.radio.amateur.moderated
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Default Tube equipment question

On Mar 4, 6:57�pm, Mike Coslo wrote:
wrote groups.com:

Most hollow-state ham rigs can handle 2:1 SWR no problem.
Sometimes there is less tolerance for loads that are highly
reactive, though.


What are the practical limitations of the Tube finals apparent
flexibility?


It's really a matter of how the rig was designed.


Many 1950s hollow-state ham rigs were built with pi-networks that
could match a wide variety of loads efficiently. The EF Johnson Viking
2 is a classic example of that type. Many
homebrew designs also had such pi-networks.


The problem is that the components for such a wide-range network tend
to be large, heavy and expensive. So in the late 1950s and early
1960s, rigmakers designed more for compactness than for wide matching
range. Still, the typical
ham rig of those days could usually handle SWR of 2:1 or
less with no problems.
Is it safe to compare the load, plate, and drive controls to some of
the functions of a tuner? (possible real dumb question)

The short answer is "no". Tuning up a hollowstate
ham rig is a similar but not identical to adjusting the
typical tuner.


Some may tell you that all it takes to tune up a tube
transmitter is to "peak the grid and dip the plate", but
that's simply not correct. Tuneup procedures vary
according to rig design and you have to be specific.
Of course once you get the hang of it, the procedure
rapidly becomes second nature.


I enjoy twiddling knobs, kind of the same way I like a manual
transmission. 8^)


It's a question of skill vs. automation.

What specific hollowstate rigs are you considering?


* * Last year at Dayton I purchased a 40 and 80 meter Heathkit single
* * Bander as a learning tool - they are pretty simple. I restored the
* * 80 meter unit, and will start on the 40 meter one sometime.


I think you mean the Heath HW-12 and HW-22, or the later
A models of the same rigs.

They are from the early-to-mid 1960s, and have very limited
matching range. They are really only meant to match a 50
ohm load. Note that there isn't even a LOADING control on
them.

The Single Banders were Heath's answer to the "SSB is too
expensive" idea. Every possible simplification and economy
measure was used in them, yet the result is a usable 100 W
class SSB transceiver for one HF ham band. Note that the
75 meter one stops at 3.8 MHz. Heath figured that by
simplifying the output pi network to the most extreme degree,
they could save a few dollars. Coming up with a 50 ohm
antenna was the ham's problem.

I am now
* * looking at a Kenwood TS-830S. It's a hybrid, with tube finals. I
* * really like it so far, although I don't see it replacing my IC-761.


That's a pretty good rig for its era. The matching range is limited
but it will handle 2:1 SWR without problems IMLE.

I am hooked on computer control of the newer rig - sometimes! Other
* * times I just like that retro aspect.


One of the great things about amateur radio today is that we can
use a wide variety of technologies for the same or similar purposes.

I find it ironic that the evolution of the "state of the art" has come
full circle in about a half-century, at least in HF/MF:

- Ham rigs of the 1950s usually had wide range pi-nets which required
adjustment, but would match almost anything without an external
device.
- Ham rigs of the 1960s and 1970s usually had restricted-range
pi-nets which were easier to adjust, but sometimes required an
external matching device.
- Ham rigs of the 1980s and later usually have solid-state finals and
no adjustment - and usually require an external matching device.

73 de Jim, N2EY

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Old March 5th 07, 02:10 AM posted to rec.radio.amateur.moderated
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Default Tube equipment question

On Mar 4, 7:09?pm, Mike Coslo wrote:

. Lots of Hams today are restricted to
one antenna, yet they would like all band operation. I think it would be a
great idea for a manufacturer to have a transciever that included a tuner
right in the rig itself.

Many rigs offer that as an option. For example, the Elecraft K2 can be
equipped with the optional KAT2 internal automatic antenna tuner. In
my experience, the KAT2 can match at least a 10:1 SWR, if not more. It
doesn't have
manual adjustments, however - it's a form of autotuner.

The 100 watt version of the K2 can be equipped with the
matching external tuner.

One interesting feature of these autotuners is that they
automatically reduce power to a few watts while the tuning routine is
operating.

I don't know of any solidstate HF ham rig with a *manual*
tuner built-in.

73 de Jim, N2EY

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Old March 5th 07, 02:10 AM posted to rec.radio.amateur.moderated
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Default Tube equipment question

On Mar 4, 3:56�pm, Mike Coslo wrote:
" wrote roups.com:

* *Failure to properly
* *neutralize a final RF amp can result in heating sufficient
* *to melt the glass envelope enough to let air in and thus
* *destroy the tube (an 833 that was mounted on the control
* *console at Army station ADA for weeks as a reminder).


* * * * I would also suspect that when dealing with 15 KW transmitters,
errors would be pretty unforgiving.

What are the practical limitations of the Tube finals apparent
flexibility?


* *That's in many decades of old literature and covered
* *extensively. *Data from commercial service transmitters
* *is more comprehensive than amateur types as a
* *general rule. *Some of that may be hard to get now.


* * * * I'm going to have to try to find some of the literature.


Besides old ARRL Handbooks prior to the 1970s, I'd suggest
finding the site that has digitized copies of GE Ham News.
Those were (bi-monthly?) hand-outs by GE to push their
tubes (naturally) but they contained lots of different ham
projects (using tubes, of course).

I found such a site a few years ago but didn't bookmark it.
Was incomplete then but being worked on. The 1960s
was a good peiod for new designs in USA amateur radio.
I used to grab my boss' copies as soon as he was done
with them back then. :-)

73, Len


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Old March 5th 07, 02:11 AM posted to rec.radio.amateur.moderated
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Default Tube equipment question

On Mar 4, 4:09�pm, Mike Coslo wrote:
wrote:


* * * * That brings up a related issue. Lots of Hams today are restricted to
one antenna, yet they would like all band operation. I think it would be a
great idea for a manufacturer to have a transciever that included a tuner
right in the rig itself.


IF and only IF they appear on some modern-day surplus
market, look carefully at an AN/PRC-104. That is a manpack
HF radio with an extra box on the side for an automatic
tuner for the whip antenna. It's been in military service
(land forces) for about 20 years now and several companies
are trying to get in with new replacements for it...Harris for
one (if I remember the military news).

Neat little thing, frequency-synthesized, SSB, can be keyed.
Designed and manufactured by Hughes Aircraft Ground
Systems. QRP of course but the military used the same
R/T for higher-power vehicular and fixed HF sets (higher
power antenna tuners, too, in those). All solid-state,
of course. I have the TM on it in PDF in case you were
really interested in that...:-)

73, Len



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Old March 5th 07, 03:23 AM posted to rec.radio.amateur.moderated
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Default Tube equipment question

"Dee Flint" wrote in
:


My main HF rig and my husband's main HF rig both have built in tuners.
Both work pretty well. However they do not have the range of
outboard tuners.


I should have noted large range and balanced/unbalanced output. My
IC-761 has an autotuner on it that works pretty well with my vertical
antenna. The dipole is run with balanced line, and needs a different
tuner.


A lot of commericial and military equipment have built in tuners with
quite significant tuning ranges. Of course this comes at a price so
amateur gear doesn't have as much range in their tuning capacity on
the built in tuners.


Size can be an issue too. The IC 761's tuner is a pretty tiny
thing. I had to take an IC 765's autotuner 9 (very similar) apart once to
repair it, and it was around the size of one of the mfj tiny tuners.

A little bigger components, plus a 4:1 balun, and they would have
it.

- 73 de Mike KB3EIA -

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Old March 5th 07, 03:26 AM posted to rec.radio.amateur.moderated
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Default Tube equipment question

wrote in
oups.com:
Some may tell you that all it takes to tune up a tube
transmitter is to "peak the grid and dip the plate", but
that's simply not correct. Tuneup procedures vary
according to rig design and you have to be specific.
Of course once you get the hang of it, the procedure
rapidly becomes second nature.


I enjoy twiddling knobs, kind of the same way I like a manual
transmission. 8^)


It's a question of skill vs. automation.


I've always wanted to know just what was going on in what I was
operating. I at least like the option betwen automatic operation and
manual. Skills can never hurt.


What specific hollowstate rigs are you considering?


* * Last year at Dayton I purchased a 40 and 80 meter Heathkit single
* * Bander as a learning tool - they are pretty simple. I restored
the * * 80 meter unit, and will start on the 40 meter one sometime.


I think you mean the Heath HW-12 and HW-22, or the later
A models of the same rigs.

They are from the early-to-mid 1960s, and have very limited
matching range. They are really only meant to match a 50
ohm load. Note that there isn't even a LOADING control on
them.


That would be the units with one exception. More on that later..


The Single Banders were Heath's answer to the "SSB is too
expensive" idea. Every possible simplification and economy
measure was used in them, yet the result is a usable 100 W
class SSB transceiver for one HF ham band.


The simplicity was what attracted me to them. No filters, nonotch,
no pbt, no RIT, no - well you get it.



Note that the
75 meter one stops at 3.8 MHz. Heath figured that by
simplifying the output pi network to the most extreme degree,
they could save a few dollars. Coming up with a 50 ohm
antenna was the ham's problem.


The 75 meter rig I have tunes to 4 MHz. It's also a HW22a, probably a
later mod. But all that simplicity is a good thing for a lad raised
mostly on integrated circuits! 8^)


I am now
* * looking at a Kenwood TS-830S. It's a hybrid, with tube finals. I
* * really like it so far, although I don't see it replacing my
IC-761.


That's a pretty good rig for its era. The matching range is limited
but it will handle 2:1 SWR without problems IMLE.


I have been pretty impressed so far. The receiver seems pretty hot,
certainly the sound is *good*. I'm listening to it right now, and it is
simply very legible. Tuning is only one speed, and a tad fast. Seems
strange just having SSB and CW, but overall I think I'll keep it.



I am hooked on computer control of the newer rig - sometimes!
Other times I just like that retro aspect.


One of the great things about amateur radio today is that we can
use a wide variety of technologies for the same or similar purposes.



I find it ironic that the evolution of the "state of the art" has come
full circle in about a half-century, at least in HF/MF:

- Ham rigs of the 1950s usually had wide range pi-nets which required
adjustment, but would match almost anything without an external
device.
- Ham rigs of the 1960s and 1970s usually had restricted-range
pi-nets which were easier to adjust, but sometimes required an
external matching device.
- Ham rigs of the 1980s and later usually have solid-state finals and
no adjustment - and usually require an external matching device.


And that is what I'm thinking about with regards to new rigs with
an internal tuner that has both balanced and unbalanced capabilities as a
natural evolution. There are a lot of Hams that don't have the ability to
put up towers and beams, and are looking at a wire antenna for a while. I
think its time for that

- 73 de Mike KB3EIA -

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Old March 5th 07, 03:56 AM posted to rec.radio.amateur.moderated
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Default Tube equipment question

" wrote in
oups.com:


Besides old ARRL Handbooks prior to the 1970s, I'd suggest
finding the site that has digitized copies of GE Ham News.
Those were (bi-monthly?) hand-outs by GE to push their
tubes (naturally) but they contained lots of different ham
projects (using tubes, of course).


Got it! Thanks a lot Len - I googled them up, and have enough reading
material to keep me busy for a while.

the site is: http://bama.sbc.edu/ge_ham_news.htm

- 73 de Mike KB3EIA -

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Old March 5th 07, 06:08 AM posted to rec.radio.amateur.moderated
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Default Tube equipment question

On Mar 4, 11:21 pm, "
wrote:
On Mar 4, 12:53?pm, wrote:

On Mar 4, 12:48?pm, Mike Coslo wrote:
Some may tell you that all it takes to tune up a tube
transmitter is to "peak the grid and dip the plate", but
that's simply not correct. Tuneup procedures vary
according to rig design and you have to be specific.


Sorry, but that was procedure for pre-WW2 high-
power HF transmitters.


Sure it was.

While it is a simplistic
phrase, it still applies. A more exact procedure
was to tune up the exciter with reduced drive
power and literally peak the grid current. Plate
current was then observed with the plate tuning
adjusted for a slight, but observable dip in plate
current. Of (perhaps) greater importance was setting
the neutralizing control for minimum grid current;
"dipping" the plate current should produce the least
grid current peak on adjusting the plate tuning.


A number of amateur transmitters/transceivers have used a quick
peaking of the drive/preselector control followed by adjustment of
tune and load controls for maximum output, keeping readings within
operating parameters. I've never seen an amateur transmitter with a
front panel neutralizing capacitor. Neutralization is normally a set
and forget procedure which one needn't worry about until the final
tubes are replaced.

Tuning for maximum output for a given amount of drive has become the
norm in tuning high power, vacuum tube linear amplifiers. All one
needs do is make certain that the bottles don't aren't drawing too
much grid current. A check of linearity can be made with the station
monitor 'scope.

The load capacitor of a pi-net has
the least effect on tuning to a new frequency.


That would depend upon the antenna being used and the amount of
frequency change as well as the type of equipment being used. Some
manufacturers switch in some fixed capacitance on various bands or
portions of bands.

The pi-network output circuit was a favorite among
amateur homebrewers for decades due to its
simplicity and better ability to attenuate harmonics...


....but the Pi-L did a much better job of attenuating harmonics with
only a little more circuit complexity. Quite a number of Novice
licensees found themselves in receipt of OO notices or letters from
the FCC when using a simple pi-net output tank with a multiband
antenna.

Dave K8MN

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Old March 5th 07, 06:09 AM posted to rec.radio.amateur.moderated
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Default Tube equipment question

On Mar 5, 3:26 am, Mike Coslo wrote:
wrote groups.com:



The simplicity was what attracted me to them. No filters, nonotch,
no pbt, no RIT, no - well you get it.


Note that the
75 meter one stops at 3.8 MHz. Heath figured that by
simplifying the output pi network to the most extreme degree,
they could save a few dollars. Coming up with a 50 ohm
antenna was the ham's problem.


The 75 meter rig I have tunes to 4 MHz. It's also a HW22a, probably a
later mod. But all that simplicity is a good thing for a lad raised
mostly on integrated circuits! 8^)


The 75m transceiver is the HW-12A. It runs 3.8-4.0 MHz. That's all
the phone band there was back when the rig was produced. There's a
mod in one of the mags--CQ, I think--that puts in a fixed silver mica
cap with a little trimmer cap in parallel for making the thing work on
both 3.8-4.0 and 3.7-3.9 MHz at the flip of a mini-toggle switch.
That'd give you a bit more room to roam.

I am now
looking at a Kenwood TS-830S. It's a hybrid, with tube finals. I
really like it so far, although I don't see it replacing my
IC-761.


That's a pretty good rig for its era. The matching range is limited
but it will handle 2:1 SWR without problems IMLE.


I have been pretty impressed so far. The receiver seems pretty hot,
certainly the sound is *good*. I'm listening to it right now, and it is
simply very legible. Tuning is only one speed, and a tad fast. Seems
strange just having SSB and CW, but overall I think I'll keep it.


In it's era, the TS-830 was somewhat of a DXer's and contester's dream
machine.
That receiver has an extra filter slot for cascading filters. One can
still buy after market filters for it.

Dave K8MN



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