craxd wrote:

Larry,

This bound to have been in the early 70's or so. I had a GTE/Philco
19" TV I took in as a trade in and I played it myself for about a
year before I sold it. I can't remember if it was all solid state or
if it was a hybrid. Seems to me they had an old paper type light
green colored PC board in them. I think they was about the first to
own the Philco name after Ford, maybe bought it from them? North
American Phillips ended up with all three names. As far as I know,
N.A.P. no longer is selling new Philcos, only Magnavox and Sylvania.

Philco was the set for a private dealer to get a franchise on as
Sylvania and Magnavox was being pushed by the large chain stores. It
was all that was available over Lowes and a few other large stores
starting to sell them in the early 80's. Lowes was who hurt me. Now,
I don't think Lowes even handles TV sets. RCA was bad to not protect
a teritory and set someone else up a mile away so I never looked at
them. I had the Quasar sales for a while also, but they got just too
hard to work with. Now they're all chain store items.

Best,

Will

--- In ham_amplifiers@... <mailto:ham_amplifiers%40yahoogroups.com>, Larry Anderson
<larryw6lar@...> wrote:

craxd wrote:

Bill,

That is exactly the truth. When I started in repair (radio and

TV),

tube sets were still around. There, you replaced parts in a

chassis

with point to point wiring. Next came addition of PC boards with
tubes, and then the hybrid sets came having both tubes and solid
state devices. After that came the modules. That was easy fixes,
however the power supplies power components like resistors, etc

were

still mounted on tie strips, etc. Zenith modular sets were my
favorite with the upright chassis. Magnavox had one similar.
Motorola, soon to be Quasar had the "works in a drawer". Next came
the replacable chassis. No more modules, they wanted you to change
the whole chassis out. Then it was only one large flimsy PC

board. I

repaired most of these anyhow and only changed a chassis after
lightning damage. First you had a chassis and a tuner. Finally,

the

one board included both. I forgot to mention that hot chassis

started

about this time or a little earlier. I was selling and servicing
Philco TV's at the time for North American Phillips. Phillips

bought

Philco from GTE. Then, all Phillips did was run the same TV set

down

the line and put 1 of 3 name tags on them, Philco, Magnavox, or
Sylvania. About this time is when the mass marketing of TV's

began by

Lowes, K-Mart, and others large chain stores. They could sell a

set

at the same price as what a private dealer could buy one for. That
closed a lot of repair shops including mine. Eventually, sets got

so

cheap that you could throw them away as the cost of repair was at
least 50-76% of a new set. This especially true for 19 inch TV's

on

down. VCR's did the same thing too. Now you can buy a new VCR for
about $50.

All that's taught for service anymore is replacing a chassis, and
most of it is building PC's. Vacuum tube technology is not taught
anywhere I know of. After some of us older folks are gone, I

wonder

who will actually be able to do real repair work anymore?

Best,

Will

--- In ham_amplifiers@...

<mailto:ham_amplifiers%40yahoogroups.com>

<mailto:ham_amplifiers%40yahoogroups.com>, Bill Turner <dezrat@>

wrote:

We seem to be casting a lot of blame on individuals, but I

believe

the

underlying problem isn't people, it is the nature of electronic
equipment these days.

A lot of us got our start by being repairmen, and to do that

kind of

work well, one must understand the fundamentals of electronics.

These

days, you either change a PC board (if it is an expensive piece

of

gear), or you just throw it out and buy another. So-called
"technicians" anymore are mostly just parts changers, not real
repairmen. I don't see that changing any time in the near

future.

Of course there are some real technicians around, but any more

they

are working mostly at the engineering level, not the field

repair

level, and there are not a lot of them because not a lot are

needed.

Once the bugs are worked out of a design, you just make 'em by

the

millions and toss the bad ones.

Sad but true.

Bill, W6WRT

Will,
Question? When did GTE own Philco? I've been with them (GTE/

Verizon) for

43 years and I only know that they owned Sylvania.Was that before

my

time there. Just wondering.

Larry, W6LAR

Will,
I think you jogged my memory as after I ask the question I seemed to remember that just before GTE sold out the Sylvania line they did take on Philco from Ford. Boy! thats a long time ago. We used to have an "Employee Store" at selected company yards integrated with our supply department and all of the Sylvania products were offered and you could purchase on "time" payment through payroll deduction with no interest. Was a great deal for those of us just starting out to get some nice electronics. I still have a few items I purchased there. Thanks for the info Will.

Larry, W6LAR

Hi again:

Further digging into details of the SIBA web site revealed a search
function:



Specifying a voltage of 6 kV gives a result for a 8 x 120 mm fuse
having a rated current of up to 4 A. I am going to try to use one of
these...

73 de Frank DG1SBG


Am 30.10.2006 um 10:08 schrieb Frank Goenninger:

On Oct 30, 2006, at 1:08 AM, Frank Goenninger wrote:

Hi all:

I am about to finish my HV power supply. One thing missing still is
an appropriate HV fuse to be put between C bank and glitch R. While
closely examining the pictures in the photos section of this group I
couldn't find any European manufacturer or distributor of HV fuses.

I found SIBA () - but they do provide fuses for
even "bigger" applications... I'd need something suitable for the 3,5
kV / 3 A coming out of my 300 ?F C bank...

Any suggestions? Thx for feedback!

Hello, Frank == A HV fuse in the secondary does not protect the HV-
transformer any better than a circuit breaker in the primary. cheerz

73 Frank DG1SBG
...

R L Measures, AG6K, 805.386.3734
r@..., , rlm@..., www.somis.org

Hi all:

I am about to finish my HV power supply. One thing missing still is
an appropriate HV fuse to be put between C bank and glitch R. While
closely examining the pictures in the photos section of this group I
couldn't find any European manufacturer or distributor of HV fuses.

I found SIBA () - but they do provide fuses for
even "bigger" applications... I'd need something suitable for the 3,5
kV / 3 A coming out of my 300 ?F C bank...

Any suggestions? Thx for feedback!

73 Frank DG1SBG

Larry,


This bound to have been in the early 70's or so. I had a GTE/Philco
19" TV I took in as a trade in and I played it myself for about a
year before I sold it. I can't remember if it was all solid state or
if it was a hybrid. Seems to me they had an old paper type light
green colored PC board in them. I think they was about the first to
own the Philco name after Ford, maybe bought it from them? North
American Phillips ended up with all three names. As far as I know,
N.A.P. no longer is selling new Philcos, only Magnavox and Sylvania.

Philco was the set for a private dealer to get a franchise on as
Sylvania and Magnavox was being pushed by the large chain stores. It
was all that was available over Lowes and a few other large stores
starting to sell them in the early 80's. Lowes was who hurt me. Now,
I don't think Lowes even handles TV sets. RCA was bad to not protect
a teritory and set someone else up a mile away so I never looked at
them. I had the Quasar sales for a while also, but they got just too
hard to work with. Now they're all chain store items.

Best,

Will


--- In ham_amplifiers@..., Larry Anderson
<larryw6lar@...> wrote:

craxd wrote:

Bill,

That is exactly the truth. When I started in repair (radio and

TV),

tube sets were still around. There, you replaced parts in a

chassis

with point to point wiring. Next came addition of PC boards with
tubes, and then the hybrid sets came having both tubes and solid
state devices. After that came the modules. That was easy fixes,
however the power supplies power components like resistors, etc

were

still mounted on tie strips, etc. Zenith modular sets were my
favorite with the upright chassis. Magnavox had one similar.
Motorola, soon to be Quasar had the "works in a drawer". Next came
the replacable chassis. No more modules, they wanted you to change
the whole chassis out. Then it was only one large flimsy PC

board. I

repaired most of these anyhow and only changed a chassis after
lightning damage. First you had a chassis and a tuner. Finally,

the

one board included both. I forgot to mention that hot chassis

started

about this time or a little earlier. I was selling and servicing
Philco TV's at the time for North American Phillips. Phillips

bought

Philco from GTE. Then, all Phillips did was run the same TV set

down

the line and put 1 of 3 name tags on them, Philco, Magnavox, or
Sylvania. About this time is when the mass marketing of TV's

began by

Lowes, K-Mart, and others large chain stores. They could sell a

set

at the same price as what a private dealer could buy one for. That
closed a lot of repair shops including mine. Eventually, sets got

so

cheap that you could throw them away as the cost of repair was at
least 50-76% of a new set. This especially true for 19 inch TV's

on

down. VCR's did the same thing too. Now you can buy a new VCR for
about $50.

All that's taught for service anymore is replacing a chassis, and
most of it is building PC's. Vacuum tube technology is not taught
anywhere I know of. After some of us older folks are gone, I

wonder

who will actually be able to do real repair work anymore?

Best,

Will

--- In ham_amplifiers@...
<mailto:ham_amplifiers%40yahoogroups.com>, Bill Turner <dezrat@>

wrote:

We seem to be casting a lot of blame on individuals, but I

believe

the

underlying problem isn't people, it is the nature of electronic
equipment these days.

A lot of us got our start by being repairmen, and to do that

kind of

work well, one must understand the fundamentals of electronics.

These

days, you either change a PC board (if it is an expensive piece

of

gear), or you just throw it out and buy another. So-called
"technicians" anymore are mostly just parts changers, not real
repairmen. I don't see that changing any time in the near

future.

Of course there are some real technicians around, but any more

they

are working mostly at the engineering level, not the field

repair

level, and there are not a lot of them because not a lot are

needed.

Once the bugs are worked out of a design, you just make 'em by

the

millions and toss the bad ones.

Sad but true.

Bill, W6WRT

Will,
Question? When did GTE own Philco? I've been with them (GTE/

Verizon) for

43 years and I only know that they owned Sylvania.Was that before

my

time there. Just wondering.

Larry, W6LAR

All,

I finished coding the first portion of the long formula calculations
in imperial measurements for the Maxwell Transformer Calc. When the
results are compared to the short formula for 12 kilogauss and 60 Hz
(see pic at view one), it's just about exact. I posted another pic
(View 4) showing the results for a 220 Vac primary and the 3000 watt
transformer for any interested.

View 1;



New View 4;



Best,

Will

pentalab wrote:
<snip>

### On the bench they measure 36 pf.... bolted into the chassis... they rise to 50-55pf. IMO, it's the proximity of the lower fins to the chassis that's causing this. Bring it down another 1"... and I'm betting it will increase substantially. It would take all of 5 seconds to measure
the exact pf in the submounted case. [nothing connected to anode]

I will measure this tomorrow and report back the difference between the
measured anode to grid capacitance unmounted and sub-mounted.

In the submount case, the tube will also have to be inserted

from

below ! IE: stuff the top of the anode UP through a min

4.94"

diam hole in the chassis.

TONY SEZ.... Not in the case of a YC-156 or YC-179. It works just

fine inserting it from the top.
### whoa . If the grid ring is aprx 5" diam.... the hole in the chassis has to be a tiny bit bigger... u drop it from above... then u would need offset metal standoffs to screw to the top side of the grid ring.... up and outwards beyond the hole in chassis.... to screw to chassis ??? Still, this would leave a huge hole immediately next to the tube... and loads of air will get through... way more than if u used a SK-306 chimney ?

No. The hole in the chassis needs only to be large enough to pass the
grid ring from the top, even snuggly. Once it is passed through that
hole it mounts on a plate an inch below the chassis. That plate can be
6" square or more if you want it to be. In the case of my GS-35B mounts
I use 1/8" copper plate which is supported by a 1" length of 4" square
extruded aluminum tube that has 116 1/4" holes around its perimeter.
Since it is unlikely you will find 6" square extruded tubing, a simple
standoff can be made using 1/4" thick flat 1" wide stock forming a
square that is 6" on a side. Fill the sides with 1/4" holes and the area
of the holes exceeds the difference in the area of the hole in the
chassis and the area occupied by the ceramic of the tube. You have
virtually solid ground for the grid with only a 5" hole in the chassis
which is nearly the same diameter as the anode. The straight tube PTFE
chimney works fine. In fact, you can turn a small lip on the bottom of
the chimney and let it protrude through the hole the thickness of the
chassis plate if you want to. As you stated earlier, it's heavy enough
to stay on the chassis itself and requires no mounting at all. You slip
the chimney over the tube after it is secured with its screws from the
bottom.

TONY SEZ... I have to wonder about suspending the tube out there

in the middle of the cross. There's a bit inductance gained grid to ground by doing that.

Plus there's a significant amount of loss in the conduction of

heat away from that flange.
### Point well taken! A ring of holes would result in least inductance. With the amount of airflow available.. the grid ring is still gonna get cooled allright. Notice how JA6TAY appears to use a large copper sheet.. and puts his tube, C1/C2 cap on it ?

Yep, and many folks ignore the large current path between the tank and
the tube.

<snip>

### 3 x YC-156's is totally stupid.[11m ops have successfully done it, they are obviously not stupid... maybe we should invite a few of em to this group, they seem to have a wealth of info.... like how to use LMR-1200 as a rotor loop, what blows up, what doesn't, who makes reliable pole pigs, once removed from the oil, etc.]

LOL! Some of them ARE smart... smarter than given credit... but I am
afraid that the majority seem to demonstrate the opposite.

## I can see two of em....barely. Even then,they would gobble up chassis space. My buddy asked Eimac if they could remove the 4.94" cooler from these YC-156/YC-179's... and install the larger 7.5" diam cooler from the 3CX-15KB7... Eimac said.. "no way".

We've discussed that also but way too much trouble. Considering that it
isn't just the fins that will have to be increased in size. You'd also
need more copper in the core to get the heat out to those fins.
Unfortunately there is a practical limit beyond which more air just
doesn't do enough good to keep adding it.

### Considering the typ "200 A" service most folks have, coax, flexible coax, 7-16 Dins, baluns,etc... with 10-20 kw pep out... you have usually reached an upper practical limit. The next 3db is just too impractical... requiring a 440 lb dahl, careful layout, obscene currents, bizzare component requirements etc. Still, it could be done.... and a fun engineering challenge... doable... but very expensive. The overall logistics can quickly get out of hand. Just toss some numbers into the various spread sheets for a lark....cheap entertainment.
Later... Jim VE7RF

I've done that with my spread sheet... it's pretty amazing the amount of
current from the 240 Volt line and that's just for the plate input
power! It is that fact alone that has opened the eyes of a few to
realize they couldn't really do some things that they "talked" about doing.

You can get another 3 dB above the YC's but any more than that and you
have all the problems you've mentioned and unless one is ready for
those, it occurs at lower power levels too.

Get back to you with those measurements.

Regards, Tony W4ZT

craxd wrote:

Bill,

That is exactly the truth. When I started in repair (radio and TV),
tube sets were still around. There, you replaced parts in a chassis
with point to point wiring. Next came addition of PC boards with
tubes, and then the hybrid sets came having both tubes and solid
state devices. After that came the modules. That was easy fixes,
however the power supplies power components like resistors, etc were
still mounted on tie strips, etc. Zenith modular sets were my
favorite with the upright chassis. Magnavox had one similar.
Motorola, soon to be Quasar had the "works in a drawer". Next came
the replacable chassis. No more modules, they wanted you to change
the whole chassis out. Then it was only one large flimsy PC board. I
repaired most of these anyhow and only changed a chassis after
lightning damage. First you had a chassis and a tuner. Finally, the
one board included both. I forgot to mention that hot chassis started
about this time or a little earlier. I was selling and servicing
Philco TV's at the time for North American Phillips. Phillips bought
Philco from GTE. Then, all Phillips did was run the same TV set down
the line and put 1 of 3 name tags on them, Philco, Magnavox, or
Sylvania. About this time is when the mass marketing of TV's began by
Lowes, K-Mart, and others large chain stores. They could sell a set
at the same price as what a private dealer could buy one for. That
closed a lot of repair shops including mine. Eventually, sets got so
cheap that you could throw them away as the cost of repair was at
least 50-76% of a new set. This especially true for 19 inch TV's on
down. VCR's did the same thing too. Now you can buy a new VCR for
about $50.

All that's taught for service anymore is replacing a chassis, and
most of it is building PC's. Vacuum tube technology is not taught
anywhere I know of. After some of us older folks are gone, I wonder
who will actually be able to do real repair work anymore?

Best,

Will

--- In ham_amplifiers@... <mailto:ham_amplifiers%40yahoogroups.com>, Bill Turner <dezrat@...> wrote:

We seem to be casting a lot of blame on individuals, but I believe

the

underlying problem isn't people, it is the nature of electronic
equipment these days.

A lot of us got our start by being repairmen, and to do that kind of
work well, one must understand the fundamentals of electronics.

These

days, you either change a PC board (if it is an expensive piece of
gear), or you just throw it out and buy another. So-called
"technicians" anymore are mostly just parts changers, not real
repairmen. I don't see that changing any time in the near future.

Of course there are some real technicians around, but any more they
are working mostly at the engineering level, not the field repair
level, and there are not a lot of them because not a lot are needed.
Once the bugs are worked out of a design, you just make 'em by the
millions and toss the bad ones.

Sad but true.

Bill, W6WRT

Will,
Question? When did GTE own Philco? I've been with them (GTE/Verizon) for 43 years and I only know that they owned Sylvania.Was that before my time there. Just wondering.

Larry, W6LAR

--- In ham_amplifiers@..., R L Measures <r@...> wrote:

The League seems to be somewhat less than serious about

thoroughly

updating and improving the Handbook. Example: In 1994 I got a
letter from the League asking me if I was interested in improving

the

Handbook. At first I laughed, but then I foolishly said yes.
Dave Newkirk, an ex-employee of the League, told me that
correcting errors made by a guru-status ARRL employee who made an
electronic mistake in a publication is virtually impossible until
well after he makes the Silent Keys column.

If I recall, I found some errors about calculating anode current, or
the terms used with it in the ARRL Handbook. It was contradicted by
the RCA Radiotron book. There was a discussion about this on the Amps
mailer at one time. Over this, I don't hold a lot of stock in some of
the published data.

If I also recall, the calculations for Pi and Pi-L nets was off and
not changed until around 1987 or 1989? I can't remember exactly what
the date was now. So the books before this are not correct. None of
them shows you step by step how to do it. The writer goes off on too
many tangents. In my opinion the text is a mess, and one is better
off consulting other books on the subject.

Should be in big
black print on page 1 of the HV pwr supply section..... or

what's

left of it. The league loves publishing books.

Selling books, Jim -- which is how the powers-that-be in Newington
get the money to Direct the so-called Directors. Here's how it
works: Directors receive varying amounts of "shaking hands money"
for going to Hamventions. Those Directors who rock the boat more
receive less shaking hands money, and Directors who rock less get
more money. It's sorta like what goes on in the RNC and the DNC.

Money has spoken for the ARRL Handbook, QST, and other publications
from the ARRL for years. One will never see correct information with
the bias caused over this.

R L Measures, AG6K, 805.386.3734
r@..., , rlm@..., www.somis.org

Best,

Will

On Oct 29, 2006, at 6:30 AM, pentalab wrote:

--- In ham_amplifiers@..., R L Measures <r@...> wrote:

On Oct 29, 2006, at 1:43 AM, pentalab wrote:

--- In ham_amplifiers@..., R L Measures <r@...>

wrote:

, and replace the RF chokes with fusing resistors.

RICH SEZ... In my experiences, a suitable glitch-R in the HV+

helps prevent grid- filament shorts.

### OK... I'll bite... why does a Glitch R prevent Grid- filament
shorts on a thoriated tungsten tube ??

IMExperiences, it takes c. 11g of force for c. 30-seconds to unbend the midpoint of a 3-500Z's filament helices far enough to straighten it following an intermittent VHF parasitic oscillation. Thus, I presume that a considerable number of amperes are delivered from the HV-PS filter-C to have been able to have bent one in the first place. Limiting the peak amperes during a parasitic oscillation decreases the perpendicular bending force

### what have u got against HV fuses Rich?

RICH SEZ.... Do you carry two spare tires in your car? As I see

it, overkill is not good engineering - except perhaps on a moon
mission if I going.

### RL Drake used a .82 ohm 1 watt reistor in the B+ as a HV
fuse.... it always blows

It is not a fuse at 2500v, it was a temporary metal vapor arc that had a v-drop of c. 20v during the period when it should have been limiting current.

...

RICH SEZ....The Henry 2k-4 has a resonant-choke filter -- perfect

for 120v operation with virtually no drop in PEP out.

### Trbl is... you would have to run a new heavy duty 20-30 A
120 V line into the shack to run a Henry 2K-4.. on 120 V.

Not true. They run FB on SSB from a 120v, 15a circuit.

In
which case, you may as well run a 240V line in the 1st place...
unless u are talking about 600 w pep out on ssb.

no, 1500 pep. Resonant-choke filter DC supplies are wonderful until you have to lift the sucker.

### Why do these Henry's weigh so much.[180 lbs].. for a 1200-
1500w pep out amp???

See above. The is no free lunch, Jim.

### a 120 lb hypersil pole pig is good for 10 kw pep out...
you could run 6 x Henry's easily.

The Plywood Box amplifier used a Peter Dahl 68-pounder with a 4500va, 13-ohm secondary for 14 pep out on ssb.

...

RICH SEZ... I disagree. Inductive loads can produce 25x the

operating potential when current stops.

### What kind of inductive load are u talking about here ??

RICH SEZ.... Even electric heaters have L.

### I find this hard to believe. You may be right though... I get
a little flash when trying to interupt an electric heater.

Indeed, Jim, indeed. An o'scope will tell it like it is. The Apollo 13 incident appears to have been the result of a thermal switch that arced when it tried to open and the arc welded it's contacts closed. A $1 MOV would have prevented the problem.

RICH SEZ...An ordinary 12vDC relay's coil can produce 400v when
the EM field collapses.

### so what ?

ignore 400v?

48 V telco' relay's from the 70's would produce
an easy 1100 V. We used to use RC snubber's to quench the
arc.... then along came the infamous VRZA15 MOV.... end of
problem. BTW.... you can series MOV's for more V... and also
parallel em for more joules... or do both. You can stick em
across anything.... except breakers.

Later.... Jim VE7RF

R L Measures, AG6K, 805.386.3734

r@..., , rlm@, www.somis.org

Yahoo! Groups Links

R L Measures, AG6K, 805.386.3734
r@..., , rlm@..., www.somis.org

On Oct 29, 2006, at 5:54 AM, pentalab wrote:

--- In ham_amplifiers@..., R L Measures <r@...> wrote:

On Oct 29, 2006, at 2:45 AM, pentalab wrote:

--- In ham_amplifiers@..., Tony King - W4ZT <w4zt-
060920@> wrote:

Pentalab wrote:

---

Some guy in W6 land wants me to design an amp around 3 x

YC-156's in parallel, GG... low band stuff. I figure with

600w of drive.. it should do 30-36 k out.

Wow... well if one tube isn't enough... you need a BIGGER tube!

I can't imagine dealing with the problems of paralleling 3 YC-
156's. He needs a 15k or 20k!

RICH SEZ.... Paralleling 3 tubes triples C-feedback, and that is

not desirable unless one is trying to build an oscillator. The
tube that is best suited for 20k - 35k out is the 8281/4cx15000A.
200w will drive one in AB1.

### So what ?

Anecdotal sure-cures don't cut the parasitic mustard.

Just install a globar type suppressor in each anode
lead. As is, the single YC-156 runs just fine wtih NO suppressor
at all.. and that's with it .75pf of feed through C to boot.
The single 3CX-3000A7 runs just fine sans suppressor with
it's .6 pf of feedthrough C. The 3CX-6000A7 has just .28 pf of
feedthrough C. We can probably toss the suppressor on that amp as
well. At this rate, we can put globar outa business.

### 3 x YC-156's is totally stupid.[11m ops have successfully
done it, they are obviously not stupid... maybe we should

invite a few of em to this group,

RICH SEZ.... guffaw

### well maybe not too stupid. 3 x YC-156's can be had for
$1100.00 vs huge bux for a 4 x 15.[plus socket]

What is Svetlana's price for an 8281?

### These YC-156/YC-179's.. with their almost 19db of gain..

Eimac says the gain is 14.2db at 6kV.

are
the 4-1000 for the new milenium... quick, where's that pole pig ?

### I'm serious....

Serious people look at the mfg's spec sheet instead of speculating.

cheers, Jim


R L Measures, AG6K, 805.386.3734
r@..., , rlm@..., www.somis.org

On Oct 29, 2006, at 5:29 AM, pentalab wrote:

To prove Rich's observation about caps blowin up when the eq
resistor opens.... I'm proposing a test. Using a variac.... dial
it up so +400 vdc appears across the string of 8 x caps [50 v per
cap] THEN open one resistor [the one at the cold end]... then
watch the V go up on the cap with the open resistor.... and watch the
other 7 x cap's Voltage.... drop.

This way... the cap with the open resistor should hit +400 vdc....
and no big bangs. IF this is the case... how come u never see it
mentioned in the arrl handbook/orr's books ?

The League seems to be somewhat less than serious about thoroughly updating and improving the Handbook. Example: In 1994 I got a letter from the League asking me if I was interested in improving the Handbook. At first I laughed, but then I foolishly said yes.
Dave Newkirk, an ex-employee of the League, told me that correcting errors made by a guru-status ARRL employee who made an electronic mistake in a publication is virtually impossible until well after he makes the Silent Keys column.

Should be in big
black print on page 1 of the HV pwr supply section..... or what's
left of it. The league loves publishing books.

Selling books, Jim -- which is how the powers-that-be in Newington get the money to Direct the so-called Directors. Here's how it works: Directors receive varying amounts of "shaking hands money" for going to Hamventions. Those Directors who rock the boat more receive less shaking hands money, and Directors who rock less get more money. It's sorta like what goes on in the RNC and the DNC.

... how about a super
thick hardcover one... just for linears ? .... done right this
time.... nah.. they would screw it up. YC-156... nah... u need one
of those $7500.00 Acoms.

Later... Jim VE7RF





Yahoo! Groups Links

R L Measures, AG6K, 805.386.3734
r@..., , rlm@..., www.somis.org

ORIGINAL MESSAGE:

On Sat, 28 Oct 2006 21:02:11 -0000, "craxd" <craxd1@...>
wrote:

All that's taught for service anymore is replacing a chassis, and
most of it is building PC's. Vacuum tube technology is not taught
anywhere I know of. After some of us older folks are gone, I wonder
who will actually be able to do real repair work anymore?

Best,

Will

------------ REPLY FOLLOWS ------------

I'm sure there will be a few guys who know how to repair a tube radio
or TV but they will become a rare breed, much like people who can
repair an ancient painting or book.

Time marches on.

Bill, W6WRT

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--- In ham_amplifiers@..., R L Measures <r@...> wrote:

On Oct 29, 2006, at 1:43 AM, pentalab wrote:

--- In ham_amplifiers@..., R L Measures <r@...>

wrote:

, and replace the RF chokes with fusing resistors.

RICH SEZ... In my experiences, a suitable glitch-R in the HV+

helps prevent grid- filament shorts.

### OK... I'll bite... why does a Glitch R prevent Grid- filament
shorts on a thoriated tungsten tube ??

### what have u got against HV fuses Rich?

RICH SEZ.... Do you carry two spare tires in your car? As I see

it, overkill is not good engineering - except perhaps on a moon
mission if I going.

### RL Drake used a .82 ohm 1 watt reistor in the B+ as a HV
fuse.... it alwys blows b4 the built in primary ckt breakers.

RICH SEZ.... 160m is the only game in town for <1000km evening

communications when 75m gets long during the Winter months.

### agreed. 160m is an excellent band for short haul stuff.

RICH SEZ....The Henry 2k-4 has a resonant-choke filter -- perfect

for 120v operation with virtually no drop in PEP out.

### Trbl is... you would have to run a new heavy duty 20-30 A
120 V line into the shack to run a Henry 2K-4.. on 120 V. In
which case, you may as well run a 240m V line in the 1st place...
unless u are talking about 600 w pep out on ssb.


### Why do these Henry's weigh so much.[180 lbs].. for a 1200-
1500w pep out amp???

### a 120 lb hypersil pole pig is good for 10 kw pep out...
you could run 6 x Henry's easily.

...

RICH SEZ... I disagree. Inductive loads can produce 25x the

operating potential when current stops.

### What kind of inductive load are u talking about here ??

RICH SEZ.... Even electric heaters have L.

### I find this hard to believe. You may be right though... I get
a little flash when trying to interupt an electric heater.


RICH SEZ...An ordinary 12vDC relay's coil can produce 400v when
the EM field collapses.

### so what ? 48 V telco' relay's from the 70's would produce
an easy 1100 V. We used to use RC snubber's to quench the
arc.... then along came the infamous VRZA15 MOV.... end of
problem. BTW.... you can series MOV's for more V... and also
parallel em for more joules... or do both. You can stick em
across anything.... except breakers.

Later.... Jim VE7RF

R L Measures, AG6K, 805.386.3734

r@..., , rlm@, www.somis.org

--- In ham_amplifiers@..., "Mike Sawyer" <w3slk@...> wrote:

I have a RCA SBA-1K Radio-marine amplifier, (2X 3-400Z's at 2800VDC)

which will do 1KW dead carrier all day long. RCA chose to use a dual
Dow-Key coax switch with BNC connectors for the input and output to
the antenna. RCA was known to overengineer (at least still in the mid
sixties) most of their radio equipment. Good enough for them.

Mod-U-Lator,
Mike(y)
W3SLK

#### can u do... say 1 kw out FM, on 29.6 mhz... with a 2:1
swr ??? Scratch that... RG-58 is only good for 450 W on 10m..
with a flat swr. I suppose a guy could use $1.10 per ft Teflon
RG-303.

### with BNC's + RG-58U.... I think you would be in trbl on 20-
10m. The BNC works good on my 2m handheld.... which resides in
the junk box these days.

Later.... Jim VE7RF

--- In ham_amplifiers@..., R L Measures <r@...> wrote:

On Oct 29, 2006, at 2:45 AM, pentalab wrote:

--- In ham_amplifiers@..., Tony King - W4ZT <w4zt-
060920@> wrote:

Pentalab wrote:

---

Some guy in W6 land wants me to design an amp around 3 x

YC-156's in parallel, GG... low band stuff. I figure with

600w of drive.. it should do 30-36 k out.

Wow... well if one tube isn't enough... you need a BIGGER tube!

I can't imagine dealing with the problems of paralleling 3 YC-
156's. He needs a 15k or 20k!

RICH SEZ.... Paralleling 3 tubes triples C-feedback, and that is

not desirable unless one is trying to build an oscillator. The
tube that is best suited for 20k - 35k out is the 8281/4cx15000A.
200w will drive one in AB1.

### So what ? Just install a globar type suppressor in each anode
lead. As is, the single YC-156 runs just fine wtih NO suppressor
at all.. and that's with it .75pf of feed through C to boot.
The single 3CX-3000A7 runs just fine sans suppressor with
it's .6 pf of feedthrough C. The 3CX-6000A7 has just .28 pf of
feedthrough C. We can probably toss the suppressor on that amp as
well. At this rate, we can put globar outa business.

### 3 x YC-156's is totally stupid.[11m ops have successfully
done it, they are obviously not stupid... maybe we should

invite a few of em to this group,

RICH SEZ.... guffaw

### well maybe not too stupid. 3 x YC-156's can be had for
$1100.00 vs huge bux for a 4 x 15.[plus socket]

### These YC-156/YC-179's.. with their almost 19db of gain.. are
the 4-1000 for the new milenium... quick, where's that pole pig ?

### I'm serious.... I think it would liven things up a bit... a
different perspective perhaps. When u start talking 20-35 kw
output... it's all.. 'illegal' anyway. Now don't start some
silly discussion about how 5 kw on 20m is... 'ok', but 10 kw on
11m is a 'no-no'. Rich... does a 8281 qualify as a....'Riley H
special' ? Me... I just boil oil. None of my tubes even have
handles. I asked Reid B, if they were gonna install handles on the
new YC-243... he wents nuts on me... said it would increase costs
through the roof..... so no handles for Jimbo here.

Later... Jim VE7RF

...

R L Measures, AG6K, 805.386.3734
r@..., , rlm@..., www.somis.org

To prove Rich's observation about caps blowin up when the eq
resistor opens.... I'm proposing a test. Using a variac.... dial
it up so +400 vdc appears across the string of 8 x caps [50 v per
cap] THEN open one resistor [the one at the cold end]... then
watch the V go up on the cap with the open resistor.... and watch the
other 7 x cap's Voltage.... drop.

This way... the cap with the open resistor should hit +400 vdc....
and no big bangs. IF this is the case... how come u never see it
mentioned in the arrl handbook/orr's books ? Should be in big
black print on page 1 of the HV pwr supply section..... or what's
left of it. The league loves publishing books.... how about a super
thick hardcover one... just for linears ? .... done right this
time.... nah.. they would screw it up. YC-156... nah... u need one
of those $7500.00 Acoms.

Later... Jim VE7RF

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