On Thu, 04 Mar 2004 19:47:59 GMT, Bruce in Alaska wrote:

In article ,
engsol wrote:

Question:

In the days of yore, did early marine radars ever use klystrons? We used them
in (very) early microwave communications systems. They were a bear to
keep on frequency, and didn't last long.

Maggies are interesting devices. If you've ever torn one apart, it mostly
looks like a machined hunk of steel, which in fact it is, and surprisingly
small.
The magnets account for most of the weight.

As to power, I recall that our airborne radar had a peak power output of
2 megaWatts, but the maggie current was only 18 - 20 milliamps. Of course
the
high voltage was 20 kV.

What kind of maggie power supply (voltage & current) is normally found in
small
marine radars these days?

Norm

Back before Gunn Diode LO's, all radars used Klystrons as Receiver LO's.
All the early Commercial Radars that came on the market after WWII used
Klystrons as receiver LO's. 2K25 comes to mind but don't hold me to
that.

Now days the radar receivers use LNA/MMIC's for FrontEnds with intergrile
solidstate LO's driving Double Balanced Active Mixers. This is why
Radars these days can see 48 and 72 miles with less than 6Kw Maggies.
Back in the bad old days it took 20 and sometimes 40Kw to see out 72
miles, because the receivers were KLystron feed Crystal Diode Mixers
with Sky High Noise Figures.

Receivers have become orders of Magnitude more sensitive than 2nd and 3rd
generation receivers of the 70's and 80's. Your Tax dollars at work.
(US MIlitary Electronics Development Dollars)

V and A for common Maggies are in the 2Kv- 3Kv range with peak currents
of an amp, and up to 2 amps PEAK. This all compes from the Pulse
Forming Network that is usually feed by a switching powersupply up in
the T/R Pan that runs on 10-40 VDC Ships Mains, or some such variation
of Power supply for the Radar. 9M502 and 9M503 come to mind for common
3-5 Kw maggies, with the old 2J42 for the 9 - 10 Kw versions. Haven't
kept up on the state of the art for the last 7 or so years, but the
basic's haven't changed all that much in the Tx side of the Antenna Pan.

Bruce in alaska
Thanks much Bruce...very helpful info. And I forgot about those diode mixers
in the rx front end. 1N34? Was that the one?
Norm

On Thu, 04 Mar 2004 18:52:46 -0800, engsol
wrote:

Thanks much Bruce...very helpful info. And I forgot about those diode mixers
in the rx front end. 1N34? Was that the one?
Norm

1N60. Looked like a little white ceramic 22-cal cartridge. You could
pull off the big end and have two pins to plug into some UHF
applications. In the radar receivers, it plugged right into the
waveguide, 1/4 wavelength from the end of the receiver cavity,
protected by a gas tube that fired and shorted out the RF while the
transmitter was on the air.



Larry W4CSC

No, no, Scotty! I said, "Beam me a wrench.", not a WENCH!
Kirk Out.....

In article ,
engsol wrote:

On Thu, 04 Mar 2004 19:47:59 GMT, Bruce in Alaska wrote:

In article ,
engsol wrote:


Thanks much Bruce...very helpful info. And I forgot about those diode mixers
in the rx front end. 1N34? Was that the one?
Norm

Yep, 1N34, 1N34A, 1N914, 1N415A, B ,C and E just to name a few.

Bruce in alaska
--
add a 2 before @

In article ,
(Larry W4CSC) wrote:

protected by a gas tube

That had a tiny bit of Strontium 90 in it to set a bias
for the Ionization of the T/R tube. Couldn't just toss
those Bad Boys in the trash, as they were a Radiation
Hazard if the were broke open.

Bruce in alaska
--
add a 2 before @

And the R or reverse polarity ones. I must admit I replaced a few of those
with the normal ones and lost a few more hairs from my now bald head trying
to figure what the new problem could be.
Doug K7ABX
"Bruce in Alaska" wrote in message
...
In article ,
engsol wrote:

On Thu, 04 Mar 2004 19:47:59 GMT, Bruce in Alaska
wrote:

In article ,
engsol wrote:


Thanks much Bruce...very helpful info. And I forgot about those diode
mixers
in the rx front end. 1N34? Was that the one?
Norm

Yep, 1N34, 1N34A, 1N914, 1N415A, B ,C and E just to name a few.

Bruce in alaska
--
add a 2 before @

Hee hee....funny you should mention that, Bruce......

We did a REFTRA in Gitmo back in 66 aboard USS Everglades (AD-24).
She was an old WW2/Korean War destroyer tender with a single screw
turned by two steam turbines and 4 boilers.

The inspectors came into my little cal lab and broke a tube marked
"radioactive" on the deck and said, "Broken Radioactive Tube!", to
which we were supposed to respond with this silly kit to put tape on
the remnants and seal it all up in a can for disposal, probably with
major reactor parts.

Ol' Larry whips out his radiation counter from a nearby bin, passes it
over the tube guts and declares it non-radioactive....sweeps it up and
dumps it in the sh!tcan.....(c;

"OK, smart boy, I'll be back!", declares the 1st class PO doing the
test......

That poor guy broke half the tubes on the ship, all the way up to the
major hydrogen thyratrons out of radars we didn't even have trying to
find a tube that would make my geiger counter show SOME
reaction.....NO-GO.

He finally says, "Well, if we COULD have found a radioactive tube,
what would you have done?" "Oh, now you ask. I'd have got out this
kit (producing kit from its place) and done this.", I declared.

I didn't have the heart to tell him NONE of the tube PARTS is
radioactive....just the gas that WAS in it before he broke it. The
gas was gone so it was a non-issue.....(c;

Try it for yourself. Get a hydrogen thyratron that's been firing a
10MW beast for a few years and measure it for yourself.

I don't know where NAV gets these crazy, paranoid ideas.....(sigh)

The big klystrons and maggies stop radiating Xrays as soon as you turn
'em off, too. Asst Chief Engineer at WTAT-24, our Fox affiliate
running 5MW ERP from a 160KW UHF transmitter has 2 klystrons over 7'
tall to the top of the boiler that cools 'em. They run 'em until the
filament fails at $32K/copy.....



On Fri, 05 Mar 2004 18:58:27 GMT, Bruce in Alaska
wrote:

In article ,
(Larry W4CSC) wrote:

protected by a gas tube

That had a tiny bit of Strontium 90 in it to set a bias
for the Ionization of the T/R tube. Couldn't just toss
those Bad Boys in the trash, as they were a Radiation
Hazard if the were broke open.

Bruce in alaska
--
add a 2 before @


Larry W4CSC
POWER is our friend!

Be aware that both regulation agencies in Canada and the US have
de-regulated certain amounts of radioactive material.

Our TR-limiters at work were de-regulated. We didn't have to worry about
signage or breakage (leave the room for the day if you're worried). As far
as I know they could be toss in the dump. I don't htink you could
incinerate them though (don't know about that!).

sb

"Bruce in Alaska" wrote in message
...
In article ,
(Larry W4CSC) wrote:

protected by a gas tube

That had a tiny bit of Strontium 90 in it to set a bias
for the Ionization of the T/R tube. Couldn't just toss
those Bad Boys in the trash, as they were a Radiation
Hazard if the were broke open.

Bruce in alaska
--
add a 2 before @

Oh ya....you have strontium 90 in those old watches who's hands glowed in
teh dark too!


"Bruce in Alaska" wrote in message
...
In article ,
(Larry W4CSC) wrote:

protected by a gas tube

That had a tiny bit of Strontium 90 in it to set a bias
for the Ionization of the T/R tube. Couldn't just toss
those Bad Boys in the trash, as they were a Radiation
Hazard if the were broke open.

Bruce in alaska
--
add a 2 before @

"Larry W4CSC" wrote in message
...
Hee hee....funny you should mention that, Bruce......

Ol' Larry whips out his radiation counter from a nearby bin, passes it
over the tube guts and declares it non-radioactive....sweeps it up and
dumps it in the sh!tcan.....(c;
/
I didn't have the heart to tell him NONE of the tube PARTS is
radioactive....just the gas that WAS in it before he broke it. The
gas was gone so it was a non-issue.....(c;
/
I don't know where NAV gets these crazy, paranoid ideas.....(sigh)

Larry, very funny story! ...but not at all accurate w/r to detection of
radioactive material, the type and emissions of which your "geiger counter"
was never designed to detect.

While we could have played similar games with inspectors, the weapons and
propulsion engineers that inspected my old missile submarine would probably
have missed the humour. ;-)

Jack in Virginia Beach

In article .net,
"Doug" wrote:

And the R or reverse polarity ones. I must admit I replaced a few of those
with the normal ones and lost a few more hairs from my now bald head trying
to figure what the new problem could be.
Doug K7ABX
"Bruce in Alaska" wrote in message
...
In article ,
engsol wrote:

On Thu, 04 Mar 2004 19:47:59 GMT, Bruce in Alaska
wrote:

In article ,
engsol wrote:


Thanks much Bruce...very helpful info. And I forgot about those diode
mixers
in the rx front end. 1N34? Was that the one?
Norm

Yep, 1N34, 1N34A, 1N914, 1N415A, B ,C and E just to name a few.

Bruce in alaska
--
add a 2 before @



Most of the 1N415x series had reversable bases, so one can have both
polarities with one product.....


Bruce in alaska
--
add a 2 before @