1954-5 ARRL 813 Rig - KC2YOI score - 500 watts??

[WBear2GCR]

KC2YOI scored this vintage 1954-5 Handbook single 813 rig. The next day I was visiting KC2JXX and he had a '54 Handbook. Looking through the transmitters it was difficult to identify which if any of them were this rig. But a look at the pix in the handbook identified the unusual 6146 with dual butterfly air variables as being the same as the one that Dylan got. The Handbook rig has a built-in VFO and a different layout in the top of the chassis than the hombrew one...

Anyhow, two things... first the Handbook calls this single 813 rig a "500 Watt" transmitter!! (maybe CW only?)
They're calling for 2000-2250 and the article says to test load it at 225ma... otoh the next article shows a single 813 rig at 150 watts, iirc and the same B+!! Wazzup wit dat??

So, what does that make a pair of 813s??

Then there is the modulator... it has what looks like sockets for 2 x 6146. Geez man, I somehow don't think that two 6146s are going to even fully modulate the 813 at 150 watts?? It's got a pretty hefty Stancor poly-match transformer in it...

Anyhow, no matter what this looks like it could be a FB rig...

                           _-_-bear

[K6IC]

Well,  Bear,

The RCA Data does say ICAS Class C Telefony 2250 VDC @ 0.225 A,  which if just over 500 Watts INPUT.  In the olden days people spoke of Input Power,  so seems that a pair just makes 1 KW input,  and about 750 Watts Carrier output.

Earlier today,  found a very good RCA 813 Data Sheet.  The earlier data on Frank's site was from the very small format RCA binders,  but this later one is much more detailed.

Frank's Tube Data site:
http://frank.pocnet.net/

RCA 813 Data Sheet:
http://frank.pocnet.net/sheets/079/8/813.pdf

72,      Vic

[KA8WTK]

I don't have the 1954 book, but......
 In the 1955 book on page 169 is a single 813 rig with no vfo that is rated at 300 watts input (1500 volts, 200 ma. plate). On page 174 is a 500 watt input single 813 (2000 volts at 250 ma.) with VFO. The 300 watt rig shows the voltage and load for plate modulation. The same rig (page 169) can also be run as high as 2250 volts for cw or 450 watts input (according to the article).
  The differences, IMHO, come from the different components used in the final tank and the power supplies. At any rate, you would have to back down the "500" watt rig to run plate modulation like they did the "300" watt rig to avoid flashing the tank circuit cap. Just like they did with the "300" watt rig. The plate spacing on both rigs looks too close in the pictures for 500 watts input of plate modulated power.
  
  

Bill
  

[Pete, WA2CWA]

Do you know for sure it came from 1954-5 Handbook?
Is there a bandswitch in there somewhere or is this set up for "10-11" meters.

If you go to the ARRL AM web page: http://www.arrl.org/am-phone-operating-and-activities and scroll down to "Three Control Six-Band 813 Transmitter". You can click on the three QST articles and the Handbook article. See if that one matches.

[K5UJ]

A friend of mine is selling me part of a hb 813 rig (actually most of it; what is missing is the meters and VFO and cabinet) It is modulated by pair 811.  I think it was meant to be driven by a signal shifter.  I have one of those, the 1941 deluxe model with 160 and 80 m. coil sets.   I don't know much about it i.e. plate v. etc. but I had been figuring on it being a 150 w. rig (output).  It's a beauty.  when I get it I'll post photos.  I always thought that classic 50s handbook 813 rig was single 813 modded by pair 811s


rob

[WBear2GCR]

Pete,

This one has the same 6146 and dual butterfly caps as does the 'YOI rig:

http://www.arrl.org/files/file/Technology/tis/info/pdf/5401011.pdf

Other differences as noted earlier...

               _-_-bear

[w1vtp]

It's possibly a variation of the 1954 813 xmtr.  If you want to see the real thing thing

http://www.qrz.com/db/w2icq

Bob is the resident expert on that rig.  Also, KA2J  Dave owns one.  It's a nice xmtr but no way it's a 500 watt rig - on phone.  As has been pointed out top rating for a 813 is 500 watts input cw, may 400 watts phone max.

Al

[WBear2GCR]

Thanks Al!

Yeah, that looks like the '54 813 rig on Bob W2ICQ's QRZ page!

Dylan (YOI) should get a kick out of seeing that...

So far all that has happened is that we've both looked at it, and he got it... it is clearly a variant of that '54 single 813 rig...

Any comments on the modulator??
Pix can be posted...

               _-_-bear

PS for the record: C. Vernon Chambers, W1JEQ(sk)  1954 single 813 rig

[Pete, WA2CWA]

It's possibly a variation of the 1954 813 xmtr.  If you want to see the real thing thing

http://www.qrz.com/db/w2icq

Bob is the resident expert on that rig.  Also, KA2J  Dave owns one.  It's a nice xmtr but no way it's a 500 watt rig - on phone.  As has been pointed out top rating for a 813 is 500 watts input cw, may 400 watts phone max.

Al

I own one too along with a homebrew power supply that weighs about 10,000 pounds.  W2ZM had one (maybe he still has it) because I remember working him when he was using it.  Mine has been on the back burner to get up and running again for the last several years. If you look at the schematic or read the QST article, it was designed as a CW rig. You can cathode modulate this rig and in the QST article a footnote referenced "The Simplest Modulator", QST, Sept. 1953. In the later QST article, he indicated a Class B modulator with a pair of 811A's and a speech amplifier/driver could be used and gave some Handbook page references

[KM1H]

I have that rig also, picked it up 2 years ago from a guy on LI that got it in NJ. We met in the ARRL parking lot and they took some pix. It is such a faithful reproduction of the original it may very well be the one built by Vern Chambers but it was also the most copied TX they featured from what I was told there.

Its in beautifull shape including the QST updates but no PS or modulator. Its a future project.

Carl

[w1vtp]

<snip>
Any comments on the modulator??
Pix can be posted...

               _-_-bear

PS for the record: C. Vernon Chambers, W1JEQ(sk)  1954 single 813 rig

Perfect application for a 811A modulator with a UTC CVM-4 or THORDARSON 11M77 or a UTC S-22-- some such mod iron.  Gin up a cathode follower as a driver and run the modulator in AB1 and it would be a killer 300 - 400 watt (input) xmtr.  Where there is no on-board VFO the possibilities are endless but a EFJ 122, EICO 722 etc (I forget the Heathkit model).  A period signal shifter would fit well especially along side the crinkle finish of the main chassies


Al

[KA8WTK]

Just a very few old pics of mine....

http://amfone.net/Amforum/index.php?action=gallery;sa=view;id=88

[WBear2GCR]

Hey hey!

It's a transmitter party!!

well if Dylan would check in we'd be on to something...

Al, when I saw the rig I basically said exactly that to YOI, pair of 811s... I think that the
Stancor iron would probably be good enough to do the job... looks like a 150watt or better
core size, do it Heising and it ought to fly.

              _-_-bear

[KC2YOI]

Oh boy, photographic evidence from the kc2yoi Mildew Manor House  

RE: 813 xmtr
I'm getting quite an education from the thread here, thanks.
The man to chat with might be the one who built the rig. He ( Lou) said he built it in 1957.
 I'll drop a dime and see what else he can tell me and if he might want to join AMfone ?
He is still licensed and had a few trapped verticals up when I bought the rig.

I suppose I should try and run it w/ the RCA 6146's just to see what smokes then clean things up and push it around with the 811's.

                                            Oh boy, here we go.....
                                                          DJ
 

[Pete, WA2CWA]

It sounds great with a cathode modulator and that's a simple project to build. If the transmitter works well with that, then move on to building a Class B modulator if you desire better over all efficiency.

[KC2YOI]

It sounds great with a cathode modulator and that's a simple project to build. If the transmitter works well with that, then move on to building a Class B modulator if you desire better over all efficiency.

Thanks Pete, I'll plug the key words in re: that and search the information catacombs here.
I know a little more than enough to be dangerous and this combo should be a good learning experience. I'll have more pics and info over the weekend.
A buzzardly transmitter for my buzzardly ladder line   

                                                          DJ

[Pete, WA2CWA]

It sounds great with a cathode modulator and that's a simple project to build. If the transmitter works well with that, then move on to building a Class B modulator if you desire better over all efficiency.

Thanks Pete, I'll plug the key words in re: that and search the information catacombs here.
I know a little more than enough to be dangerous and this combo should be a good learning experience. I'll have more pics and info over the weekend.
A buzzardly transmitter for my buzzardly ladder line   

                                                          DJ

From my previous post: You can cathode modulate this rig and in the QST article a footnote referenced "The Simplest Modulator", QST, Sept. 1953. Lots of operators used this one or some simple variation. That's what I plan to use. All those QST articles mentioned are available for both members and non-members.

[KC2YOI]

OK, found it, good stuff. re: "The Simplest Modulator", QST, Sept. 1953.

Bear, what happened to ya', where did ya go? Look what you started...... 

[WBear2GCR]

I can't seem to locate a link to the Gardner "Simplest Modulator" article... any help?

           _-_-

[W2ZE]

I can't seem to locate a link to the Gardner "Simplest Modulator" article... any help?

he's talking about the well maligned ARRL. They have QST articles for all QST's starting at #1, on thier website. A very good, but overlooked resource because of the hatred toward the league sometimes on this board.

[WBear2GCR]

I searched the ARRL site, did not come up... I am not a member...

Oddly enough I commented on the circuit here, two years ago... imagine that?
Hard to think that I did not recall it... heh.

http://amfone.net/Amforum/index.php?topic=13682.0

                _-_-bear

[Vortex Joe - N3IBX]

I can't seem to locate a link to the Gardner "Simplest Modulator" article... any help?

           _-_-

Methinks it's in the 1956/57 ARRL handbook. They use a 6Y6 as the modulator and two 6S?? as the speech amp tubes. it's all built on a smallish chassis and plugs into the jack where the CW key would go, or into the cathode of the 813 or whatever tube you'd care to modulate.

Verykewl indeed and you don't need a class B modulation transfoma!

[KX5JT]

Does it reach 100% modulation?

[WBear2GCR]

In theory, it seems to me - no first hand knowledge - that it will permit the tube to turn on fully, which would be darn near 100%, but there is no way to go beyond that point... one could set it up with asymmetrical bias, and a zener (for example) that would keep the maximum negative swing from cutting off the tube... assuming that the modulator CAN cut the tube off now... I'm just talkin' out mah hat.

                 _-_-bear

PS of course this is different than plate modulation that can go beyond the CW carrier max... more like controlled carrier modulation, it seems to me...

[WA2ROC]

I'm looking at a 1954 edition of the Handbook and on pages 172 thru 176 is the "500 Watt Multiband VFO Transmitter"  just like W2ICQ has on QRZ site.

There's also a "Simple Grid Modulator" on page 250 with 6Y6's (one for each 200 milliamps of plate current) that can be used for the 813 transmitter.

A friend and his dad built one of these in the 1960's.  Maybe it was the one that KM1H bought.  Their calls were WA2SUB and WA2SUC, Ken Steenbuck, Jr. and Sr.  I went to school with Ken Jr.