ID this multiplier chain ?

[KC2ZFA]

some time ago I came into possession of the
pictured piece. Looks military/commercial.
I've traced the rf plate circuits (6ag7 untuned
buffer, 1614 1st multiplier, 6146 2nd multiplier)
but can't make heads or tails on what the
other 1614 (top of 2nd picture) is supposed
to do...its circuit appears incomplete with
some groupings of components (mainly
resistors and bypass caps) near it unconnected
to anything else.

Hope to find out if there's a schematic out there
in order to see what kind of vfo fed the 6ag7.
That ceramic feed-through at the top is just begging
for an 813 to be connected to it !

Thanks, Peter

[KM1H]

Thats neat and the discussion should be moved to the Tech forum where more will see it.

I have a 13.56 MHz Henry industrial exciter(part of a 1500W Perkin Elmer system) Im trying to decide how to do what yours already does, put on at least 80-20M. Its a 6AG7 xtal oscillator, 2E26 driver and a 4-65A final.

Carl

[KC2ZFA]

OK, if it belongs to the Tech section then by all means, those
with the power to do so please move it.

Thanks for moving the thread.

Carl, this coming week I'll do a neat drawing of the rf part and
post it along with complete coil info for anyone who wants
to duplicate it. The variable caps are Hammarlund RMC-250-S.

Here's a shot of the underside...the unconnected parts are in
the upper right hand side of the pic.

Any info will be greatly appreciated.
Peter

[W2PFY]

That is from a Westinghouse MW-2 short wave transmitter. There are pictures of it here on this board. You can also look me up on QRZ and see the transmitter with the link provided. If you look at my other pictures on there you'll find the complete down loadable MW-2 Maintenance book with schematics. That 6146 in there drove a 4-250A but in my Westinghouse I use a 4-400 which is the IPA. That drives a WL5736 tube to 3KW output on CW or 2.5 KW on AM. I run the transmitter well below that output

BTW That unit requires 100 milliwatts of drive from 2-5 mc, It has a 75 ohm input. I can run mine down to 1.850 without a problem. I think it has grid block keying. That's what that other 1614 is for.

http://picasaweb.google.com/WW2PFY/W2PFYStationPhotos#

http://picasaweb.google.com/Captionmarvelous/WESTINGHOUSEMW2#

[KC2ZFA]

BTW That unit requires 100 milliwatts of drive from 2-5 mc, It has a 75 ohm input. I can run mine down to 1.850 without a problem. I think it has grid block keying. That's what that other 1614 is for.

"are you a god ?" 

Perfect info. Many thanks.

The schematic is on pics 47 and 48 of PFY's manual so I'll only be posting
the coil info later should anyone want to build this driver.

Peter

[W2PFY]

I think the output is up to 30 MC.

Glad it helped you. It took me about two years to get all the parts I needed for the transmitter. It's been off the air since Sept 2007 but will come to life this next spring. XYL is having a battle with breast cancer so I did not have time to fix the generator that runs it. I generate my own power here at the camp. The generator is three phase at 30 KVA.

[KM1H]

See how easy that was.....location, location, location.

Its given me some good ideas also.

Carl

[KC2ZFA]

Referring to PFY's online manual, L1002 is identical to L1004, while
L1001 is identical to L1003.

L1001: 30 turns close-spaced, then a 31st turn (tapped) to get a separation
of 5/16" between the 30 turns and an additional 23 turns. Looks like 21/20
awg enamel wire, 1" diameter phenolic form. The 31st turn is tapped.

L1002: 6 turns, then a 7th turn (tapped) to give separation of 5/26" between
the 6 turns and an additional 7 turns. Turns are spaced one wire diameter.
Looks like 21/20 awg wire, 1" diameter phenolic form.

L1005: 5 turns spaced to occupy 13/16". Looks like 21/20 awg wire, 1"
diameter phenolic form.

L1010: 3 turns, air-wound, space to occupy 14/16". Looks like 14 awg
tinned wire, 1" diameter.

Here are shots of the first five:

[KC2ZFA]

and a shot of the sixth:

[W2PFY]

Now all you need to do is locate the rest of the transmitter. In a way, that's what I did. I located a Westinghouse WL-5736 PA tube at a ham fest. The guy had two and wanted $30.00 each for them. I purchased one.

Before Christmas of 2002 the three main parts of the MW-2 was for sale on ebay in California. I put a bid on it thinking I would not win and that some local would buy it because of a possible very high freight bill. Turns out I won it and had all 1600 pounds shipped in two huge boxes from way out there. I had no coils whatsoever for it. I made contact with people on QRZ and now have every part of it except the control panel and crystal oscillator.

They even made a linear amplifier for this monster that was probably for RTTY and CW. Later the modulator section was dropped for a huge matching SSB generator that also produced AM. That was called the MW-3. I think I am the only person that ever had all three pieces at the same time and got it on the air. People just part these things out I see parts out there that I know came from the MW-2 at flea markets and on ebay.

[KC2ZFA]

Now all you need to do is locate the rest of the transmitter.

doing something like this would be equivalent to "suicide by copwife" 

I'm reading up  on VFO design (I like the high-C circuits) to put together
a 2-5 MHz job, switched in 500 kc steps.

One question for all: the input of the Westinghouse 6AG7 buffer has 78 ohms to
ground (image 47 of your manual).
Should I remove that in order to feed-in a VFO using capacitive
coupling ? It looks like biasing is coming in from the cathode/suppressor.

[W2PFY]

What I did out board is have a 50 ohm resistor non inductive in parallel with the input of the MW-2 preamp-doubler, possibly a tripler and drove it with a Icom IC-746. I adjusted the transceiver output as low as it would go and it worked fine. On 40 meters I had to increase the output of the IC-746 for proper drive. Ralph, W3GL actually was in charge of a station that had a number of these used in Greenland if I'm not mistaken. He told me they used a VFO made by General Radio. I don't know the model. Maybe Ralph would remember? There are six resistors in there in parallel that provide the 75 ohm input.

Now as far as your question is concerned, I guess you could give it a try but I wonder if removing those resistors may make  unstable?

 One other note, the rectifier put out 400 volts positive and 400 volts negative at 1 amp. That was due to the fact that one rectifier could operate up to six transmitters at the same time on reduced power.  

[Ralph W3GL]

    No Terry, NOT General Radio; NORTHERN RADIO...  105's, etc...

[W2PFY]

No Terry, NOT General Radio; NORTHERN RADIO...  105's, etc...

Ok Fine