Am 24.09.2006 um 10:47 schrieb pentalab:

--- In ham_amplifiers@..., Frank Goenninger <frgo@...>
wrote:

Am 24.09.2006 um 09:52 schrieb pentalab:

### Millens are fine up to 5 kv. For the 5-10 kv stuff....
I'm going to go to a better connector.

Which ones would these be?

### Probably either Alden or Kings or Rowe. All 3 x brands
have good connectors rated at 25 kv and more. These red/black
Millen's are just too mickey mouse. The Phenolic material
will eventually absorb moisture.

### Perhaps a google on... " High Voltage connector's" will turn
up some answers........ it usually does.

;-) It did help. All of them say "I'm the best". That's why I kept asking here. Tnx for sharing your experience!

73, Frank DG1SBG

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

Do getters stop working when the HV is applied? ... when the

drive is applied? ... or when both are applied?

### getter's [per Eimac and Svetlana] are ALWAYS working...
as long as the fil is lit. HV + drive are not part of the
overall process.

ANY and
all residual gas and junk is absorbed by the getter's... and
you will never get any surprises... like any arcing from
anode to the grounded grid !!

I've fired up several gassy tubes, the insides glowed blue, but

none of them arced to the grid.

### Are u talking about 3-500Z's and 4-1000's ???? [glass
tubes] I have had new 4-1000's that glowed blue. It was
not gas either.... it was an anomoly/defect in the glass....per
Eimac. The glass would glow blue.... only when drive applied.

### Then I have also seen 4-1000's that glowed blue INSIDE the
anode/screen/grid compartment..... dunno if that was with drive
applied or not...... that was too long ago.

### With a big ceramic triode/terode.... I highly suspect... If
it's gassy... and BOTH HV and drive are applied.... arcs MIGHT
occur between anode to screen... or anode to grid.

### If the vac isn't good and hard in the 1st place.... that
could easily create even more problems.

### I had several 4-1000's yrs ago... that looked like a smoke
bomb going off inside.... when the fil V was applied!! They had
either a lousy vac.... or..'had gone to air'.

### did u ever see a blue glow inside the ceramic portion of a
metal tube ?? Kinda tough to see..with the chimney on.

### All I was trying to get at was.... if 16 guys say to use
48 hrs to getter a new/rebuilt tube.... and anything less is
gonna be a problem... cuz they have tried many diff time
frames... who am I to argue?

### Svetlana claims their tubes are proccesed at a higher temp
than Eimac [during the construction of the tube]... one would
think the Svetlana tubes would have less of a 'gas' problem
than an Eimac ?

### The Svetlana tubes all use a 'spiral mesh fil' and
where all the mesh criss crosses... they are welded. ... so
u don't wanna slam the fil V on.. it can buckle the mesh fil
sideways..esp with over rated fil xfmrs [eg: I use a 80 A
rated fil xfmr on my 50 A rated 3000A7]......... another reason
to step start em.

## I don't have the time or patience to inadvertantly destroy
expensive new/rebuilt tubes.

Later... Jim VE7RF

...

R L MEASURES, AG6K. 805-386-3734
r@...

开云体育

--- In ham_amplifiers@..., PA3DUV <pa3duv@...> wrote:

Also the SHV will accept RG8U coax only.

### If that's the case... then it will also accept Teflon RG-
393 coax.... which is a bit smaller OD than 8-U/213-U [.390"
OD for 393 coax.... vs .405" OD for 8-U /213-U
Jim VE7RF

Actually the H+S SHV is the same type as the Kings HT connectors,

a bit flimsy.

I just browsed the site. (Thanks

Greg!)

These look better to me, are mechanical sound, accept 11/12 mm

coax as well and can be supplied with nice bend restrictors.

Cheers, Dick
PA3DUV

Gents

After reading the material from Both Eimac and Svetlana...
[extending tube life via proper fil v management] a few yrs
back... I thought I would give it a try.

At my former workshop location... the power line regulation was
terrible.... so I researched SOLA constant volatge xfmr's...
and other ferroresonant xfmrs.

I managed to obtain a used SOLA 750 VA unit that's kinda
unique. It was not only regulated.... it was also 'harmonically
neutralized'.[has a pair of small oil caps in it]. It also had
3 sets of primary taps.... for 120 vac... 208 vac... and 240
vac......slick. Good so far.

The output of this thing is a constant 236/118 Vac [new ones are
all 240 vac, mine's an old one]. It's 236 vac output... with a
center tapped sec. The manual stated.. " all 3 x loads... leg
1 to neutral... leg 2 to neutral... and across the 2 x hot
legs... when added up.... can't exceed 750 VA. Good so far.

These things will handle a HUGE +/- voltage range on any of
the 3 pri taps.... and still output a constant 236/118 vac.

I tested it by wiring the pri for the 120 vac tap.... then
used a 0-132 vac variac... with the variac's OUTPUT feeding the
INPUT of the SOLA. With the variac set below 120 vac... the
sola's output V was slightly higher than 236/118 vac. With
the variac set HIGHER than 120 Vac..... the OUTPUT of the sola
dropped a tiny bit below 236/118 vac.

Even with the variac set as low as 50 vac... the sola still put
out 238 vac.

The constant output of the Sola is normally fed to the INPUT of a
small 5 A variac [240/120, depending on the fil xfmr used]. The
now CONSTANT Voltage output of the variac, is of course fed to
the primary of the Dahl fil xfmr!

Install a new 115 vac HOUR meter between one hot leg of SOLA
and center tap of the Sola. [output of sola]

I used either 1 or 2.5 mh rf chokes [100ma rated is plenty] ,
and placed one per leg.. at the socket. Other ends are fed to
both a 0-10 vac panel meter and a pair of banana jacks [stuff
ur Fluke 87-A true rms meter in there]. Both the panel meter
and the banana jacks have a 1 k resistor in each leg + .01 uf
bypass caps. The resistor's will limit the current to a safe
level if anything shorts out... and won't affect ur reading's.

We also use a simple DPDT toggle.... to switch the metering
from the socket.. to the Fil xfmr Secondary. Reason is... so
we can measure the V drop in ALL the wiring, lugs, any cross
connects.. and the 80 A bifilar choke . You will typ see
between .3v and .4v for the v drop. Most of that is coming
from the bifilar. The point here is.. to get say 7.0 v at
the socket.... ur gonna need 7.3 to 7.4 v at the xfmr
secondary.

Dahl fil xfmrs [and all other's] rate their fil xfmrs UNDER
FULL LOAD. Typ no load on a fil xfmr is usually 10% higher.

Factor this in, in any GG linear... that uses a high current
Bifilar.

Now Rich will tell you to float the xfmr.. and use a tiny
bifilar in the 240 vac primary... and this works good...BUT...
the floated xfmr MUST be installed in the RF deck.. below the
chassis. That just adds another 23 lbs to the RF deck...
tipping the scale... and making it very difficult for one person to
get the RF deck in and out of the rack.

I always use a high current Bifilar [80 A or less]... and mount
the 66lb Sola, 5 A Variac, 23 lb fil Xfmr.... in the next
shelf below the RF deck. Short, flexible heavy gauge pair of
wires interconnect the two. [typ 2 ga]

I also install a 25 ohm 100-150 w wire wound /metal finned
resistor in one leg of the Dahl fil xfmr primary.... and also a
0-30 second... 8 pin octal time delay relay is used to shunt out
this same resistor [ after 5-10 seconds] With a Dahl 240 vac
primary on the fil xfmr.... it works out that the Fil V is
exactly 75% of rated V ..[until the 25 ohm resistor is shunted]

I include the fil step start so I can leave the variac alone.
Also... in the event of a commercial AC power failure... the step
start sequence just sequences again [when power comes back on].

If You are gonna use the variac as a 'step start'.. u have to
remember to turn it DOWN after you shut off the amp. [also
during a power failure]

Now we can finally 'manage the fil V for extended tube life'.

Both Svetlana and Eimac state that on these big metal tubes...
[THORIATED TUNGSTEN FILS ONLY].... that fil emmission INCREASES
in the 1st 150-200 hrs !! [new or rebuilt tube] .

After gettering the tube for the 1st 48 hrs [at rated fil V
measured at the socket, NO HV]... one can now fire up the
HV ..and apply drive.

Eimac and Svetlana state.. after 150-200 hrs [I use the 200 hr
number], fil V can be REDUCED.

Here's what I did. After the 200 hrs is up on the hr meter......
while pulse tuning the linear [amp running full bore, perhaps a
BIT more than full bore] .. reduce the fil voltage, by turning
down the variac... till PEP power output JUST starts to DROP !!
THEN increase it a tiny bit... like .1 to .2 V.

Now my buddy with the new Svetlana 3CX-6000A7 has just done
this... and his fil V [measured at the socket] is now sitting
at 6.0 volts !! [The rated fil V for a 6000 is 7.0 volts]

Fil V is checked once in a while... and the idea here is... IF
you see that the emmision has dropped off at all... you increase
the fil V until power output is back up.

IE: tweak the variac, until PEP power output is just on
the 'hairy edge'... then increase the fil v another .1 to .2 v.

Follow the above procedure... and you will easily get 35,000
hours from the tube !! [4 yrs in a 24/7 situation]. In a 'typ'
6 hrs per day scenario... that equates to 16 yrs !!!!

Once the emmision is down, such that you have to increase the fil
V ABOVE the tube's nominal rated fil V..... then you have 2 x
option's. Either crank the variac UP, so fil V is now above
rated fil V [never go more than + 5%] OR send it back for a
rebuild.

Both Eimac and Svetlana say to just send it back for a
rebuild. I'm inclined to partially agree.. since once you have
the fil V ABOVE rated fil V.... tube life will drop... FAST.

As you can see, I and other's..take this .. 'filament
management for longer tube life' very seriously.... ditto with
the fil step start / commercial power failure scenario.

One other important thing...when finished for the night [or
day]... after turning OFF the fil... ALWAYS let the blower run
for a good 10-20 mins. We use a blower.. 'over run'
circuit.....consists of yet another Timer module... "delay on
OFF" type. These are usually 11 pin octal types.


Always remember.... when the fil is lit...'the clock is ticking'.

Later........ Jim VE7RF

On Sep 24, 2006, at 2:18 AM, pentalab wrote:

After all that discussion on the ...'other reflector' about
gettering tubes, I thought I'd add my 2 cents worth.

After reading about the detailled gettering info on Svetlana's
website years ago... I made some enquires.

Svetlana depicted the 4 x getter's on ur typ thoriated
tungsten tubes [metal monsters] as 4 x discs... located at the
TOP of the tube [the pix they had was with the anode cooler
removed].

The 4 x getter's are HEAT activated by the FILAMENT !

I was gonna fire up the filament and blower [NO HV]... and let
it run at rated fil V [measured right at the socket] for a
good 8 [EIGHT] hours.

I use 1-2.5 mh chokes... one per leg.. located right at the
fil lugs to measure fil V. The test leads are brought up to
both a 0-10 vac panel meter... and also some banana jacks [so my
Fluke 87 can be used as well] . I used a 1 k resistor in each
leg + .01 uf bypass cap's at the panel meter/banana jacks. If
the jacks, etc were ever shorted... the resistors would limit
the current.

Then came a ton of e-mail from Economy Electronics + some
amp builders plus a load of 11m QRO builders.

Apparently.... the real method is to run just the filament[s]
{NO HV] for a SOLID 48 hours !!! They all told me my
origional 8 hr plan was flawed... and they had all gone through
this dozens and dozens of times.

After the 48 hrs is up.... HV + drive can be applied.

Do getters stop working when the HV is applied? ... when the drive is applied? ... or when both are applied?

ANY and
all residual gas and junk is absorbed by the getter's... and
you will never get any surprises... like any arcing from
anode to the grounded grid !!

I've fired up several gassy tubes, the insides glowed blue, but none of them arced to the grid.

...

R L MEASURES, AG6K. 805-386-3734
r@...

开云体育

After all that discussion on the ...'other reflector' about
gettering tubes, I thought I'd add my 2 cents worth.

After reading about the detailled gettering info on Svetlana's
website years ago... I made some enquires.

Svetlana depicted the 4 x getter's on ur typ thoriated
tungsten tubes [metal monsters] as 4 x discs... located at the
TOP of the tube [the pix they had was with the anode cooler
removed].

The 4 x getter's are HEAT activated by the FILAMENT !

I was gonna fire up the filament and blower [NO HV]... and let
it run at rated fil V [measured right at the socket] for a
good 8 [EIGHT] hours.

I use 1-2.5 mh chokes... one per leg.. located right at the
fil lugs to measure fil V. The test leads are brought up to
both a 0-10 vac panel meter... and also some banana jacks [so my
Fluke 87 can be used as well] . I used a 1 k resistor in each
leg + .01 uf bypass cap's at the panel meter/banana jacks. If
the jacks, etc were ever shorted... the resistors would limit
the current.

Then came a ton of e-mail from Economy Electronics + some
amp builders plus a load of 11m QRO builders.

Apparently.... the real method is to run just the filament[s]
{NO HV] for a SOLID 48 hours !!! They all told me my
origional 8 hr plan was flawed... and they had all gone through
this dozens and dozens of times.

After the 48 hrs is up.... HV + drive can be applied. ANY and
all residual gas and junk is absorbed by the getter's... and
you will never get any surprises... like any arcing from
anode to the grounded grid !!

My buddy [who I designed the 3CX-6000A7 for] followed the 48
hour sequence on a Svetlana 6000A7.... and we never have
experience any arcing, or other anomolies... yet.

I had him install a new hour meter on the primary of the Dahl
filament xfmr.

I thought the 48 hour gettering process was.. 'pie in the
sky'... but it worked very well. I figured if a ton of
fellows had allready experimented with various.. 'gettering
times'.... and all had reached this 48 hour min conclusion, who
was I to question it.

They all told me this process pertains to both brand new
tubes.. and also rebuilt ones you get back from Eimac / Econco.

Just to recap... it's 48 hrs... with rated fil V [measured
right at the socket], blower on.. NO HV.

I have never had a 3000/6000 arc.... yet.

Now, I dunno about tubes that went through the 48 hr
process.... then down the road... were pulled from service.. and
onto the shelf for a few years. I'd be inclined to re-
getter em again for another 48 hrs... prior to application of
B+ and applying drive.

later.... Jim VE7RF

--- In ham_amplifiers@..., Frank Goenninger <frgo@...>
wrote:

Am 24.09.2006 um 09:52 schrieb pentalab:

### Millens are fine up to 5 kv. For the 5-10 kv stuff....
I'm going to go to a better connector.

Which ones would these be?

### Probably either Alden or Kings or Rowe. All 3 x brands
have good connectors rated at 25 kv and more. These red/black
Millen's are just too mickey mouse. The Phenolic material
will eventually absorb moisture.

### Perhaps a google on... " High Voltage connector's" will turn
up some answers........ it usually does.

later........ Jim VE7RF

I have found Huber+Suhner (Switzerland) but their SHV type

connector

is rated at 3.5 kV rms / 5 kV DC only.

connectors/

hs-p-rf-con-gr/hs-p-rf-con-gr-series/hs-p-rf-con-gr-series-shv.htm

73, Frank DG1SBG

开云体育

I have been using Belden 10 KV test prod wire for the last
several years.... comes in red/black. I use both red/black on
everything......... vey flexible.... abot .21" diam.... silicone
rubber. Many fine strands inside. Test V is 29 kv.

Funny thing is, the smaller 5 kv test prod wire has a test V
of 20 kv.... go figure.

My real concern using this stuff EXTERNALLY like between RF
deck and HV supply... or HV supply to an external cap box is
it would appear to be very easy for something to cut through
it. It needs to be re enforced on the outside.

Back in 1976... our local emporium had 40 kv stuff.... but had a
solid teflon dielectric... was stranded inside... and NOT very
flexible.

Anybody know the V rating on RG-303 TEFLON coax ???

My other idea was to place the Belden 10 kv silicone test prod
wire INSIDE some plastic tubing. I also saw VERY flexible
aluminium BX sheath material at home depot. Also saw the
flexible plastic tubing with the slit all the way through
it... to make life easier getting wiring inside it.

I have seen some fellows place the HV supply very close to
the main 200 A breaker panel..... then run longer lengths of
HV wiring... sometimes inside conduit... to the remoted RF
deck. The idea there was to minimize V drops in the 240 wiring.

The peak current every 8.3 msecs in the 240 V ac line is
unreal.... like almost 4-6 X.

Later...... Jim VE7RF

Am 24.09.2006 um 09:52 schrieb pentalab:

### Millens are fine up to 5 kv. For the 5-10 kv stuff....
I'm going to go to a better connector.

Which ones would these be?

I have found Huber+Suhner (Switzerland) but their SHV type connector is rated at 3.5 kV rms / 5 kV DC only.

hs-p-rf-con-gr/hs-p-rf-con-gr-series/hs-p-rf-con-gr-series-shv.htm

73, Frank DG1SBG

Am 24.09.2006 um 09:38 schrieb pentalab:

--- In ham_amplifiers@..., Frank Goenninger <frgo@...>
wrote:

### I'm going to attempt to post some pix in the photo area..
IF I can figure it out. I'm no PC geek. Worse comes....
I'll e-mail some to u direct.

Jim

Thanks, Jim! If you want me to post them in this group at yahoo please let me know!

Meanwhile I was able to find a movie on WWW showing you in the shack with some pictures of homebrew stuff. I especially love that photo with the cat. Hi-Hi!

73, Frank

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

Let me correct this:



Jim said: This is my "external cap box". I used Millen Red/ Black

HV

connector's on it. IF using the Millen's.... either use
nylon mounting screws or mount em on Micarta. Both Kings and
ROWE make better HV connector's imo.

Where can one find the Kings or Rowe connectors?

#### Try a google on kings or rowe. SSON has some.... so
does Jerry Thompson at Economy electronics... in Loanoke Ark.
He has a website too. ..think it's Economyelectronics.com



The only thing I have in my junk box are the Millen Red and the
brown phenolic. I understand the brown ones *aren't* very good.

## They are not. Only use the red/black ones.


However, my local parts jobber confided in me that the Millen
connectors were supposedly rated for 4500 VDC.

### Millen rates em at 7 kv. U HAVE to mount em from the
inside to use em at high V. Mount em on the outside.... and
I had one arc to the chassis once... and another arc to the
machine screw holding the millen down.

## Trbl with mounting em on the inside is... with 1/8" thick
panels I use... the mating screw on connector will butt up
against the panel 1st.

## If u mounted em on insulating material... they would never
arc.

### If the RF deck/HV supply is all in one box.... don't mess
with connectors... just hardwire everything with sta-kons
[solder em, as well as crimp em] on each end.. and heat shrink.

### Millens are fine up to 5 kv. For the 5-10 kv stuff....
I'm going to go to a better connector.

Later..........Jim VE7RF

Mod-U-Lator,
Mike(y)
W3SLK

--- In ham_amplifiers@..., Frank Goenninger <frgo@...>
wrote:

Am 23.09.2006 um 15:41 schrieb pentalab:

I couldn't resist.

I'm dying to see some beautiful pictures of all those neat things

you

describe... Please be so kind and put some into the photos area

of

this group on yahoo.

Mni tnx de Frank DG1SBG

### I'm going to attempt to post some pix in the photo area..
IF I can figure it out. I'm no PC geek. Worse comes....
I'll e-mail some to u direct.

Jim

--- In ham_amplifiers@..., "Paul Christensen"
<pchristensen@...> wrote:

The boys on the contest reflector finally figured out the same

thing. The typ W2DU baluns using 303 teflon coax.. and the
tiny type 75 beads would heat up with just a 500 w dead cxr on
all bands from 1.8 to 30 mhz. They switched to type 43
small beads... and the same small 303 teflon coax.[slightly
longer.. more beads] They ran the exact same test as b4.....
except 2200 watts.... zero heat ! ..."

Jim, I like air wound baluns best. But as you point out, the

geometries can oftentimes get in the way. In the alternative, I
have successfully used a combination of #43 and #77 material on RG-
214. The #43 material is used on the ends with #77 beads sandwiched
in between over a distance of ~ 60 inches. That can create some
weight and manipulation problems too. In that case, it's tough to
beat the W1JR or W2FMI technique of winding RG-303 (at 1.5KW level)
onto large #31 mix cores. I believe the DX-Engineering baluns are
constructed this way.

Paul, W9AC

#### Tnx Paul. The W1JR baluns on Array Solutions site are
rated at 5 kw....... which is the rating of 303 @ 10 mhz !

### Z goes up to the square of the turns. Of course...
winding 393 on a torroid is impossible...... hence sliding beads
over 393.

### Some have experimented with type 43 beads at the ant end....
followed by type 77. It's the beads closest to the ant feedpoint
that are gonna heat up.

### The weight/bulk/windload of solenoid coax wound baluns is
a
real pig. I'd never do it again.

Later.....Jim VE7RF

开云体育

On Sep 23, 2006, at 3:31 PM, Tony King - W4ZT wrote:

R L Measures wrote:
<snip>

Lifting an 85lb transformer is not easy for this old fart.

A small fold up Engine Lift can solve that and many other heavy lifting
jobs. One of these helped me lift my mill and lathe when I brought them
home and I have a 164 lb Peter Dahl to move too ;)

I used a sledge hammer handle, a strap, a hook, helper-girl on one end of the handle, and me on the other end to lift it in place.

73, Tony W4ZT




Yahoo! Groups Links

R L MEASURES, AG6K. 805-386-3734
r@...

R L Measures wrote:
<snip>

Lifting an 85lb transformer is not easy for this old fart.

A small fold up Engine Lift can solve that and many other heavy lifting jobs. One of these helped me lift my mill and lathe when I brought them home and I have a 164 lb Peter Dahl to move too ;)

73, Tony W4ZT

Dick,

You can buy a 1-2 ton chain fall hoist from harbor Freight for about
$40.00. One can mount this in the ceiling stationary by the hook, and
pull a pick up truck under it allowing the lift (if the ceiling is
high enough). It takes about the same amount of room as a come-a-long,
but is way easier to use. One can build some dollys to set the
equipment on and move it around the shop where ever you want.
Actually, One could mount the hoist outside to get it higher in the
air for a larger truck if you have a hard top or corcrete drive way to
roll the dolly on. They also make a set of wheels that riggers use to
move heavy machinery the same way. You can sometimes find them on ebay
at a cheap price.

If I was to use a hoist of any kind, I'd strongly recommend obtaining
a small I beam about 8 inches high at least, and set it atop two walls
to carry the load. Then mount the hoist to it. You can run these
between ceiling joists and set the ends on top of the sill plate. A
lot of the time, you can buy one cut new pretty cheap. A scrap yard is
another place to look. You only need one about the size that some
place over double-car garage doors in place of a header when they use
brick.

A luxury is to get is a small fork lift if you have a garage. Here,
they come in at the local two scrap yards all the time. To be honest,
there's not much wrong with some. A buddy of mine who owns a small
machine shop bought one from one of the yards that was electric and
they threw in a charger. I rebuilt the drive board and got it going. I
think he got it for $0.08 a pound which was $0.02 over what they paid.
I think it was one by Yale, however it was white in color. They are
very nice if your going to be doing a lot of heavy lifting. You can
mount a boom on the forks and you have a built in crane. I ran my
welding/repair portion of my machine shop with two lift trucks this
way.

Best,

Will



--- In ham_amplifiers@..., PA3DUV <pa3duv@...> wrote:

Lifting an 85lb transformer is not easy for this old fart.

I just put an M24 2 metric tonne lifting eye on a 1ft studbolt

through the steel reinforced concrete ceiling of my garage to get the
30 kVA 1500 rpm diesel genset and HT power supply on and off the
trailer. Using a chain come along even a physically challenged person
like the undersigned can do the job ;-)

Cheers, Dick
PA3DUV



----- Original Message -----
From: R L Measures
To: ham_amplifiers@...
Sent: Saturday, September 23, 2006 1:37 PM
Subject: Re: [ham_amplifiers] Re: HIGH SWR / HIGH REFLECTED POWER

SHUT DOWN CIRCUIT !!

On Sep 23, 2006, at 1:35 AM, pentalab wrote:

> --- In ham_amplifiers@..., PA3DUV <pa3duv@> wrote:
>>
>> Great info Jim!
>> NOW we're talking amplifiers ;-)
>>
>> This yahoo group has the possibility of posting pictures, files

and

> the like. Some pics of your "QRP" amps (They also make the usual

10

> kw 5 kw.. 2.5 kw qrp slugs.) would be very much appreciated.
>>
>> Thanks again for the very interesting contributions!
>>
>> Cheers, Dick
>> PA3DUV
>
> ### Tnx Dick..... As soon as I can figure out this pix posting
> deal... We will try and get some pix up.
>
> ### Just to set the record straight. I design this QRO stuff
> [including everything downstream like baluns, LC networks for
> stacked arrays, etc, for ... "clients" [who will remain
> nameless for obvious reasons]
>
> ### IMO.... I could care less how one gets their ERP. 1500w
> into stacked yagi's is... "OK".... but 5 kw into a dipole is
> a "no-no" ..gimme a break !
>
> ### These 1500-2000w amps just bore me to tears. IMO... it's
> just as easy to build a big one as a small one.

Lifting an 85lb transformer is not easy for this old fart.

> To me, it's an
> engineering challenge.

Indeed.

> ... since you will never read any... "how to
> build a 5-15 kw linear" in any ARRL hand book / QST article.

The laugher is that W1AW had an Alpha 2, 8877 amplifier until the
ARRL sold it to because it had a habit of zapping 8877s. The
purchaser of the amplifier, QST Editor Mark Wilson, installed a

low

VHF-Q parasitic suppressors and apparently put the amplifier to

good

use.
>
> ### When AES / RF Parts / Coaxial Dynamics tell me they
> sell 10 kw slugs like popcorn.... it's blatantly obvious this
> QRO scenario is, and always has been.. alive and well.
>
> ### Eimac tells me their is this... "secret world wide
> underground network of QRO amp bulders ".... so secret.. they
> don't even know each other !!
>
> ### For a laff... check out JA6TAY's site. He doesn't mess

about.

>
>
> ### Well, the cat's out of the bag now ! I fully intend to post
> as much of these "trade secrets" as I can. None of it is
> rocket science really.

Amen to that.

> It starts off as an engineering
> problem... reverts to a... "sizing issue" then back to an
> engineering issue.
>
> ### All as it amounts to is ... either using bigger
> components.... or doing stuff like paralleling 8 x 200pf @ 15
> kv HEC ceramic doorknobs to make a plate block cap assy.

With one or two thousand ohms of of RL, 1600pF is not necessary

for

the DC blocker cap at MF/HF.
>
...

cheers, Jim

R L MEASURES, AG6K. 805-386-3734
r@...