UTC PA-309 Transformer

[ke7trp]

I searched the net, Then searched through UTC catalogs.  Cant seem to find this one listed.  Its heavy. I cant lift it.  200lbs? There are six inputs on one side.  Center tap with 6 outputs on the other.  Two listed 4800-Two at 6000 and two at 7000 volts. 

Was it used in a BC rig?
What is the Current rating?

Thanks!

Clark

[AB9ZG]

What is the Current rating?

1 amp DC, I think. Check your catalogs for "CG-309", the later notation.

[KE6DF]

Right, it's the same as the CG-309 except a different case.

It has two primaries for 115 v which can be used in parallel or series. Each primary is tapped for 105v hence the six terminals.

I have a CG-308 which is the same except 1/2 the current (and half the weight )

Attached is catalog page for the PA-309.

If you build a power supply with it, be sure to put wheels on the bottom.

[ke7trp]

Only an Amp and huge.  W7TFO just stopped by the house and looked at it.  He guessed it was 1 amp. Right on the money.  I think its best to scrap it.  A modern transformer is half the size and weight and I dont actualy need this thing.

Thanks for the information!!!!

C

[KA2DZT]

I think, the PA series predates the CG series,  I have info on the PA series but have to dig it up.

Later, Fred

[WA1GFZ]

I run CG310 rated for 3000, 3500, 4000VDC 600ma CCS
The 309 is bigger. I bet it will do 1A CCS since it is lower voltage than the CG310.
My low tap on the primary is 108V

[KE6DF]

Only an Amp and huge.  W7TFO just stopped by the house and looked at it.  He guessed it was 1 amp. Right on the money.  I think its best to scrap it.  A modern transformer is half the size and weight and I dont actualy need this thing.

Well, if you don't want it, I'll take it off your hands.

You never know when you might need an anchor for an oil tanker or something.

Seriously, it can probably put out 3 KVA all day and all night -- and not overheat even in Phoenix weather.

[Opcom]

Don't scrap it.. I have one of those and it will run 1A all day long and not break a sweat. It's real quality. Some of the weight is in the end bells but still no reason to scrap it. Its potted and will last forever. It also has dual primaries. When I got mine in a trade years ago I called UTC and the engineer said it was the same part as the CG-309 except the case style was an older one. I remember the day I put it in the trunk of my Pontiac Ventura. It was heavy then and I think it is heavier now. Currently it is on a small frame with casters. If the first offer falls though, I'll come get it if only to save it from the scrap man.

As for what it was designed for - it is a standard UTC product. I don't know what commercial gear it might have been used in. Mine came from KRLD - 1080 in Dallas and was in the crate.

[KE6DF]

Turns out I'm going to be in Phoenix next week for a Bridge tournament in Scottsdale.

We own a house in Phoenix, and I grew up there and come fairly often.

The house is the house I grew up in, and if I ever want to build a really big QRO rig that would be the place to do it.

My dad was an electrical contractor and when he bought the house in 1956 he put in a small commercial air conditioner -- a water cooled unit with a water tower in the back yard.

Anyway, the AC was a 3phase unit, and that house has a 200 amp three phase electrical service to this day.

That AC unit was scrapped about three generations of air-conditioners ago.

Dave

[Opcom]

Turns out I'm going to be in Phoenix next week for a Bridge tournament in Scottsdale.

We own a house in Phoenix, and I grew up there and come fairly often.

The house is the house I grew up in, and if I ever want to build a really big QRO rig that would be the place to do it.

My dad was an electrical contractor and when he bought the house in 1956 he put in a small commercial air conditioner -- a water cooled unit with a water tower in the back yard.

Anyway, the AC was a 3phase unit, and that house has a 200 amp three phase electrical service to this day.

That AC unit was scrapped about three generations of air-conditioners ago.

Dave

There were a very few of those early tower type units in Dallas. A/C was very expensive in the old days.

[W7TFO]

I grew up in Yuma, AZ.  A fellow resident Ed Hansberger, held the patent on that AC system and either built or licensed hundreds of them all over the Southwest.

We couldn't afford one, but a neighbor had one and it used ammonia as the refrigerant and a slow, belt-driven compressor.  I remember playing in their back yard to the sound of a man-made waterfall in the wooden tower condenser.

Their house was always cool.

73DG

[k4kyv]

The house is the house I grew up in, and if I ever want to build a really big QRO rig that would be the place to do it.

My dad was an electrical contractor and when he bought the house in 1956 he put in a small commercial air conditioner -- a water cooled unit with a water tower in the back yard.

Anyway, the AC was a 3phase unit, and that house has a 200 amp three phase electrical service to this day.

That AC unit was scrapped about three generations of air-conditioners ago.

An ideal place for one of those BC transmitters that run off 3-phase power. It can be difficult to impossible to have 3-phase power run to a residence.  I even recall Timtron saying that WBCQ runs its 50 kw transmitters off single-phase because they can't get 3-phase to their transmitter site. Now if your place has room for some strapping towers and antennas...

[Opcom]

So Clark, you are going to let Dave get it, right? no scrapping?

[KE6DF]

[Now if your place has room for some strapping towers and antennas...

Unfortunately it's just a normal small city lot.

But on the plus side, there are no CC&Rs and no HOA.

No one had thought of those things back in 1956 when the house was new.

[k4kyv]

The UTC PA and CG series are electrically identical, except for case style.  PA means Public Address and CG means Commercial Grade.  Their LS series (Linear Standard) underwent the same case style changes, but they didn't change the LS designation.

The cores are identical too, but they rotated the open frame types 90 degrees so that the profile is narrow and tall, instead of the original wide and low. Looking  through some of my old UTC catalogues, I see that some of the LS series transformers significantly changed specs but kept the same type number.  Some of the older and newer driver transformers  have vastly different turns ratios, and some of the power transformers originally had 2.5v filament windings that were changed to 6.3v keeping the same type number.  That must have been confusing (and possibly disastrous) when replacing crapped out transformers.

OTOH, Thordarson seems to have randomly changed their type numbers almost annually.  If you want to look up the specs on a certain transformer, you need the catalogue for the year of manufacture.  Later editions may show a transformer with identical specs, but the type number is completely different.  Must have been a marketing gimmick, but makes it hard to find the specs on a Thordarson hamfest find or the crapped out transformer in a piece of equipment.

[KE6DF]

The cores are identical too, but they rotated the open frame types 90 degrees so that the profile is narrow and tall, instead of the original wide and low.

The end bell type LS transformers also changed from low and wide to tall and narrow.

I have an LS-67 which is the old low/wide version, and the dimensions for the same unit in the 1949 catalog show it higher and narrower.

The "cube" shaped LS transformers kept the same shape.

In addition, the paint color changed when UTC went to from the PA to the CG series. From dark charcoal/black to a gray color.

I did see a catalog from one of the distributors (Allied? Radio Shack?) from about 1948 where both the PA and CG versions were listed for sale. In that catalog the CG's were black just like the PA's.

But I've never seen a black CG transformer in real life.

[KA2DZT]

I don't think the chokes were the same.  I have PA-104 chokes and they differ from other UTC chokes.  That PA-309 is rated at 1amp.  Big enough to power any big AM plate mod xmtr.

Fred

[k4kyv]

The older LS series cubes are made of cast iron, painted black.  The newer versions originally were black, then  charcoal grey, then lighter grey.  The casting is more precision, and it is some kind of lighter weight alloy, looks like pewter.  They call it Hypermalloy. Interestingly, although it is supposed to be a good magnetic shield, it is not attracted by a magnet.

The earlier PA and LS series end bell types also came in two distinct styles.  The earlier ones were more squared off at the corners, the bakelite terminal board covered most of the entire end of the bell, and the terminals were made of some kind of black composition material, like hard rubber.  The later versions were more rounded at the corners, the bakelite terminal board took up less of the end of the casting, and the terminals were white porcelain ceramic.  According to my old catalogues, that change took place about 1938-39.  The change in style from PA to CG was in about 1948-49.

Starting a couple of years after WWII, the variety of transformers listed in the catalogues began to steadily dwindle.  Each year some of the LS series and others were discontinued.  I have a 1958 catalogue that is practically worthless as a reference because the majority of transformers I encounter are no longer listed.

[W7TFO]

Speaking of UTC, here is where it is today:

http://www.magnetika.com/

They show a few of the old types.

73DG

[Opcom]

not much on the website, I guess it is all high end custom to order.

[Opcom]

I know I have measured the 'DC' resistance of the secondaries including the taps, but can't find this now.

I was not able to do the primary measurements as are less than 1 Ohm, IIRC, need to be measured with a MilliOhmmeter.

Does anyone have those secondary or primary measurements? Need for Duncan PSUD or LTSpice.

(Hope the PA-309 in the topic didn't get scrapped.)

[W7TFO]

I wound up with it, no scrappage going on here .

When I get time, I'll shoot the windings with ye olde Ohmmeter and report back.

73DG

[KD6VXI]

Clark always came up on some oddball stuff.   I'll give him that.

--Shane
KD6VXI

[N2DTS]

I have a bc610 plate transformer on my basement floor, its been there for 20 years, in about the same spot, I use it for a step stool.
Its the early style with the 100 pound cast iron end bells, its too big and heavy to use, and its big and heavy for no reason.
Its too big to even throw out...

[KE6DF]

Wow. I thought I'd entered a time warp.

I had this thread marked to notify me when anyone posts to it.

All of a sudden I started getting emails that someone had posted to a PA-309 thread.

Say what?