w0zus transmitters

[k0vvx]

i am the luck fool that aquired 2 and hauled 8 of w0zus,s transmitters.. now here is the issue some of the parts that would have been nice to get went to abouther ham.. dose anyone know how he did his remoting set ups? these units were compleatly controllable from anouther room is how he had them set up..any help would be appriciated.

[WBear2GCR]

Well, if remote operable one would expect to see something electro-mechanical in the transmitters that would do that work. Is there anything? If so what? Jpegs?

                           

[Todd, KA1KAQ]

No, not really. It's basically a matter of accessing the circuits you need from another location, like power on/off, HV, and audio. Example, if you run toggle switch in parallel with a similar switch used to turn on the power, it works the same as if you flipped the one on the transmitter itself. Same goes for other circuits. Audio runs can be trickier.

Basically you need to decide what you want to operate and monitor remotely, and build it up. This assumes you'll be tuning it up locally, of course.

Jay N3WWL used to use his Raytheon RA-250 remotely, complete with closed-circuit television to monitor the metering.

[k0vvx]

I belive every thing is remote except tunning. there is 9 add reelays that is in the controlling circut..i will get some jpegs up loaded later today.

[NS5F]

I've been working with W5TMG on Dewy's RCA 1R2. What we have found in regards to how Dewy "thought" is the following.
1) Since the rigs were located away from the operating position there are numerous "fail-safe" control interlocks on the RCA.
 
1A) Dewy used a number of time delay relays which provided a form of step start. He must have had a number of 220v Potter/Brumfeld relays as the 1R2 has a bunch.

2) From what we've discovered the VFO input is LOW impedance, and the TR sequence provided remote PTT keying to the VFO (unknown type) plus a return "tally" to indicated the VFO was providing drive.

3) The "Kill Switch" function is part of the control interlock and when enabled removes all 220v relay coil control voltage and HV contactor coil voltage as well.

4) In the RCA 1R2 Dewy did an incredible amount of re-engineering in the transmitter especially in the control/interlock arena. It is good thoughtful engineering but a bit of a maze without a schematic. With the assistance of another ham we drew up a control circuit schematic which allowed us to see the proverbial forest instead of the single tree.

5) In the RCA 1R2 it appears that the vfo buffer was modeled along the lines of the Johnson Ranger/Viking 2 with slight differences including the LOW impedance input.

If there is anyone of Dewy's friends who recalls what he used as a station VFO for the RCA 1R2 he used on 75m we would be curious to discover what aprox drive level the VFO provided. We "think" it was on the order of up to one watt of RF into the VFO buffer..

Thanks
NS5F

[KB5MD]

An RCA 1R1 can be driven directly into the grids of the 4-400A's thru a coupling capacitor with no buffer.  Any rig outputting about 25 watts will do the trick.  I use a solid state rig with digital readout for a driver/vfo with a small tuner in line to take care of any mismatch.  Works!

[NS5F]

True on driving the 4-400(s)
Dewy switched out the 4-400(s) in both the RF and modulator. The rest of the audio looks pretty much RCA with the 2E26(s) driving the 4-125(s) modulators

In Dewy's 1R2 he has also replaced the RCA oscillator with a home-brew input buffer 6AK5 followed by a 6146 driving (2) 4-125(s). The input tank on the 6AK5 is low to hi impedance. Possibly 50 ohm input.

There is also a 6AQ5 being used as a clamper for the 6146. It looks like the classic Ranger/Valiant arrangement.
The 6146 has 350v on the plate and working with screen voltage I'd guess it's running about 35w which is within the range needed. But I've yet to get the 6146 to show Ip. Seems the clamp tube is wanting something I've not found...yet

He did such a fine job on the transmitter I'd hate to change to the external 25w drive you mentioned and since W5TMG has a real nice TMC VFO I'd like to possibly build up a solid state driver to handle the Hi/Low impedance mismatch into the 6AK5 input tank. That said if I can't wrap my head around the circuit that will probably happen. Also we're trying to nail down the use of a second 6146 as well which means we've got to get the trusty pad and paper out to reverse engineer what he did and why...

If the truth were told, this isn't really a 1R2 anymore. Pretty much all of the RCA is gone. But he did do a great job, I just wish I had more documentation...

[flintstone mop]

K0VVX
Too bad you missed out on the remote control components.
And you now have 8, as in eight?? transmitters?
You have a lifetime project to get these things back on the air.

There is a lot of help here. There are many ways to skin a cat. Some PIA may be experienced. Any way to find the Ham op who picked up on the remote control parts??

I hope your operating position is in the same room or GARAGE as the transmitters. That would simplify some of the remote control. Basically PTT?? If you need to turn power on-off, and remotely control a VFO, then there are some headaches ahead.
Some pics will be nice. Then the gang here can help you figure out how to reconstruct remote control. I am thinking, keep it simple.
Consider moving your operating position to the building where the transmitters are located.
Fred

[kb3ouk]

Fred,
If I read the post right, he only has 2 of the transmitters for himself, but he hauled 8 of them out of the place.

[flintstone mop]

Fred,
If I read the post right, he only has 2 of the transmitters for himself, but he hauled 8 of them out of the place.

YUP "Lucked 2 and hauled 8"
STILL........Try to have the operating position close to the transmitters.
Probably the reason I acted so fast to get rid of the RA250, was that it sat far away in the garage. When it was time to think about going on the air during the Winter, the last place I wanted to be was in the cold garage (25 degrees) and firing up the Raytheon. Then, actually using it, was only seeing the watt meter jump up to 250 watts and not hearing any clunking relays or getting toasty warm from the tubes.
IF I were capable of thinking things out about 7 yrs ago when we moved to Pa., I shudda built a separate shed/Ham Shack and had a 60 foot steel tower here instead of the present operation. I would be embarrassed to make public the amount of money we made from the last Real Estate boom and the sale of the QTH in Oxon Hill Md.

[K5UJ]

This is the reason why so far, I have avoided getting a broadcast rig.  I did get a Sparta thanks to W9LRS but it was (this may have been a mistake due to my inexperience at the time) deemed by me to be in too bad shape to get back on the air.  All the same, it has provided many many excellent parts for me (no selling anything off on eBay) but I know any bc rig in my future at my QTH will require structural changes to the house.  I know about doing the remote thing in the garage, but to me that is not the same.  At least half the pleasure of big iron is the sight of it, the sounds, the temp rise, plus I want to completely monitor its status and I do not trust the thing with a camera on the rig and a monitor in the shack. 

For now I am sticking with gear that can fit in 5 to 6 foot racks and shorter as they can get into the basement no problem.

[Steve - K4HX]

Having done both, remote and local, local is more fun. But, remote is better than not at all.

[flintstone mop]

Hey Rob
You should look for some old pics of K2PG and his living room Collins 20V's....Phil's present location is the big Collins 5KW version, three phase power!!!
Before marriage, I had a kitchen radio room with a HB TX and a Gates BC-1H.
I tried to find some links of pictures to my chatter here and cannot find anything. The AM Window had some interesting pics. I guess they are rotated now and then.

And Steve, YES, remote is goodness, knowing that a BC rig is making nice audio.
Who was the Ham (Eric) W? BB? something??? lived on a small mountain in Va. and had so many goodies and a beautiful CCA TX that disappeared, along with tons of iron. His son was reckless with his Dad's Amateur radios. I could never get in touch with the son after Eric's passing, to visit. It was a 5 hour drive from my QTH in Maryland. So, he was in a very remote area.
I hope this isn't hyjacking, but it connects with the passing of a great Amateur radio guy and his stuff, his station is lost forever.

Fred

[NS5F]

Steve/Fred
You're right you can't beat the "live and local" "ther-clunk" of the HV contactor pulling in and seeing the rig up close. I'm lucky since a) I'm in Texas and winters are mild, b) the shack is an attached two car plus garage that's never seen a car. I like the look of the line up here of the Western Electric 451, the Gates BC1T, and the two Collins AN/URC32(s) sitting side by side close at hand.

We're closer to getting Dewy's not RCA 1R2 on-line. The hangup is the lack of documentation. We've had to hand draw everything to figure it out. If Dewy's not 1R2 was still "RCA" it would be a piece of cake but anything good takes extra work they say..

I hope the fellow who ended up with the rest is good at reverse engineering things or else he hopefully got docs. Otherwise he'll be real busy for a while.

[WA3VJB]

... lived on a small mountain in Va. and had so many goodies and a beautiful CCA TX that disappeared, along with tons of iron. His son was reckless with his Dad's Amateur radios. I could never get in touch with the son after Eric's passing, to visit. It was a 5 hour drive from my QTH in Maryland. So, he was in a very remote area.//

Fred

WB4VVI, ended up as W4VVI
Had a CCA AM1000D, pair of Amperex 7527A modulating another pair.

[flintstone mop]

Thanks Paul,

[kb3ouk]

Fred,
Here's Phil's 20V's you mentioned: http://k2pg.com/Roomdiv.htm
Looks like you used to have quite the setup of BC rigs a few years ago, too. Couldn't find the Gates, but here's a pic off of AM Window of a Collins and McMartin: http://amwindow.org/pix/htm/kc4mop03/kc4mop1.htm
Bet that got warm with all those big transmitters in there.

[flintstone mop]

THanks Shelby
Those are good memories.
Phil has not posted any new pictures of the new QTH and the Collins 31E??? not sure about that.

[kb3ouk]

It's a 21E. 3CX2500A modulated by 3X3000A's, 5 kw ouput.
http://k2pg.com/Cottagepage.htm
http://k2pg.com/21Eproject.htm

[flintstone mop]

Thanks Shelby
Phil does things right.

[KL7OF]

Local IS a lot more fun.............................

[NS5F]

I'm glad to report W5TMG and I along with several other hams figured out W0ZUS's NOT RCA 1R2.
After learning many new swear words and filling several big chief tablets worth of drawings the old girl is alive.

Here's what we found...
First and most important is the transmitter was converted to 40 meters, not 75 meters as everyone had assumed.

note: "assume" = "a$$-u-me"

After finally wrapping our collective heads around the control circuits everything functions as engineered by W0ZUS.
The home-brew replacement for the 1R2 oscillator was in reality a buffer/multiplier
Fed the BNC with the TMC VFO @ 3.625 and what do you know! Out pops 250 watts.
Everything on the rig now works as Dewy had engineered it to work. The bias supply is a little fussy because of all of the wire-wound pots that have a little oxidation. This causes the 4-125 modulator tubes to blush a little more than we'd like and drive will sometimes mysteriously vanish but is handled with a "tweak" with the screwdriver.

The last bit of "wonky" was low modulation. It was real clean but about 35 percent. It seems that Dewy had installed an H Pad on the audio input so since the current audio chain is used on other AM rigs at +4 we removed the PAD to allow the DA to not have to run at +10 to keep the distortion low.

Thanks for the input from the forum, it gave us guidance on how Dewy had his transmitter plant wired.
The guy was one heck of an engineer and I wish I'd had a chance to know him.
Now on to the next project 
73
NS5F