small space problem

[N3DRB The Derb]

it never occurred to me that a 4 or 5 gang loading cap might want to occupy the same area as the tubes did.  There's no way to make it fit as far as I can tell unless i get funky with a right angle drive.

other pic shows one of the new plate chokes getting ready to be installed in the morning.
Might have to drill a thru hole and mount it on the tube subchassis. Suckas tall.

[Vortex Joe - N3IBX]

other pic shows one of the new plate chokes getting ready to be installed in the morning.
Might have to drill a thru hole and mount it on the tube subchassis. Suckas tall.

Timmy,
         I really like your new plate choke. It appears very well made (and neatly wound) and is probably overkill for the 4 811A's you have in the amp right now. It has more than enough headroom for a quad of 572B's with 2400 volts on their plates as well.

Question: When you install the 572B's are you going to use a outboard plate transformer for more plate voltage? Also, what are the bias supply requirements for the 572B's at the higher plate voltage? A quick and dirty bias supply could be as simple as some 9V batteries in series aka: as in old buzzard rigs using 22.5 or 45V B batteries for the same purpose. I know you understand the technology OM!

The 811A's you have in there now are rated at Zero bias when operated with 1250 or less plate voltage.

Regards,
           Joe N3IBX

[ka3zlr]

Hmmm,.. Acreage at a premium,...Welp, add on to the roof...

[N3DRB The Derb]

Joe,

I'm not going to change anything in that dept - thats the one thing Gonset got right was the power supply - they scrimped and cut corners on a lot of other things but the iron is heavy and choke input, and stock it's got 20 mf across it. Very stiff supply for a SSB linear. Damn thing weigh 88 pounds in the cabinet.

We were getting 225 watts carrier while testing it, and that was with all the crappy stock stuff in it. The 811's were good for about 125. The limiting factor is the current - the plate voltage is the same at around 1600. but you can load the 572's to 1000 ma max. 4 of them have 10 X the plate dissipation of 4 811A's.

When I get it going I'll be dropping the 572's in there. I just had the 811 in here for photo purposes. I told the guy to build the plate choke for 4 572B's @ 1700 volts/1000 ma max, and thems what I got.

too bad I'm back in the band switch business again. Maybe I can find something bigger that will take the RF current.

I forgot to tell you, when I ran my old buzzard HB rig years ago I ran a EverReady cat of 9 tails bias battery on the 805's at -22.5 volts. Cardboard box with the cat on it. You could still get them then also in 45 volts and 90 volts. worked great! Can you still get them?

[Todd, KA1KAQ]

I forgot to tell you, when I ran my old buzzard HB rig years ago I ran a EverReady cat of 9 tails bias battery on the 805's at -22.5 volts. Cardboard box with the cat on it. You could still get them then also in 45 volts and 90 volts. worked great! Can you still get them?

Here ya go, Derb - everything you could axe for in obsolete batteries (or a good start):

http://www.rfidbackup.com/Eveready/Eveready.html

and

http://www.youdoitelectronics.com/id642.htm

VERY reasonable prices, IMO. No more scared cats on the side, just a basic industrial design. Wonder how long one of those big 9volt jobbers would last in a smoke detectors?   


Ratshack of all places has the 45v, online only. Be sure you're sitting down...

http://www.radioshack.com/product/index.jsp?productId=3087907

[Vortex Joe - N3IBX]

Ratshack of all places has the 45v, online only. Be sure you're sitting down...

http://www.radioshack.com/product/index.jsp?productId=3087907

YOWZA!

[W3RSW]

That's right in line with inflation. 

There's always 5 each 9 volt batts. in series; about the same dimensional volume and price (unfortunately) unless you get a bargain bag of 9's.

I'd hate to have to duplicate a 90 volt batt. these days.

[Todd, KA1KAQ]

Considering the limited need for such oddities in today's world, I think those prices are quite reasonable. Except for the Ratshack price, double what it's available for elsewhere. That was included mainly for shock factor.

Looks easy enough to cobble some together for old 3-dailer TRF receivers, something to play with this coming winter perhaps.

Joe, I bet you can put a few of those to use!

[N3DRB The Derb]

yeah those prices are very good. thats about what I paid 15 years ago for the 22.5.

Here's the cats meow: still got the cat. I'm amazed the chinese have not picked up the logo and brand like they have everything else.

[Vortex Joe - N3IBX]

Joe, I bet you can put a few of those to use!

Todd,
       You betcha! I had to make a quintet of 9V batteries in series to replace the 45V battery used as a bias supply in my Hallicrafters HT-9, and it worked out FB. The HT-9 came with a 45V battery from the factory, as the "quick and dirty" bias supply for the 814 final tube. The original one probably lasted over 10 years. I can't understand why more people don't use battery packs for their bias supplies, albeit for a 304TL, that require a LOT of negative bias on it; I think something like 300 volts. That's a total of 33.3 9V batteries in series!

BTW, Multi-Elmac used a 22.5V battery to put bias on the 6L6G modulator tubes in them. You could get 15-20 years out of them with light usage. The current draw on the battery is miniscule.

Actually, you can make a nifty quick and dirty 90V "B" supply by stuffing 10 ea. 9V batteries in a USPS small priority mail box. I put three taps on the top with brass machine screws, having a terminal at negative,45V and 90V.(some battery TRF sets require only 45V or 67.5V for their RF stages, and 90V for the audio output) I then covered the thing in a scan from a old "Burgess" B battery label. You can't tell the difference between an original B battery, and the homebrew re-creation. The small USPS priority mail boxes are free for the taking at your local PO, and the 9V batteries came in twin packs from the "Dollar Store"  Definitely a quick,cheap and dirty method of making your own "B" supply!

If you or anyone else would like a copy of my battery label scans, just email me at: n3ibx@verizon.net. I'll send them to you in the .JPG format. I also have some for plain white tube boxes that you can "spruce up" - hi!

Regards,
          Joe N3IBX

[Todd, KA1KAQ]

Here ya go, Joe - from one of the above links:

http://www.rfidbackup.com/Eveready/images/EV493.jpg

300volts, ready to bias some unsuspecting 304TLs. There are 22.5, 45, and many other useful voltages in the list.

Your cardboard Priority mail battery sounds slick, the multiple taps adding a lot of utility. I wonder if it would be possible to cobble one together with rechargeables, or maybe refitting the standard alkalines isn't that bad? Hiding it all in a Burgess wrapper is a wonderful idea, the icing on the cake. I remember someone making a similar battery for the Zenith Transoceanics back in the 90s, correct size and worked perfectly, but the box wasn't even close to looking original. Think the guy had the name of his company on the side with some posies or such. Must've thought 'outta sight, outta mind'.

I wonder if these batts would work for that lovely copper-lined superhet you were reviving a year or so back? You must've gotten that going long ago and moved on to something else. Sweet piece-o-gear. Fun stuff to play with, and the original type batteries make it that much easier. 

[N3DRB The Derb]

it would be really cool to run a trf on 160.  if? what's a if?

[The Slab Bacon]

I built multi tapped "B" batteries for older battery sets some years back by stacking 9v transistor radio batteries. I usually used whatever was on sale cheap at the time I needed them. I used to solder jumpers from terminal to terminal, soldering Fahnstock clips at the desired taps that I needed for the set I was playing with.
(90, 67, 45, and 27v etc)

Here is a thought that I always pondered. I wonder if anyone out there ever stacked any of those high capacity "flat pack" batteries that they used to use in the film and battery packs for stuff like Polaroid cameras and the like. Those batteries were fairly high in voltage and current capacity, and quite thin. I often pondered that stacking them would make strapping but compact "B" battery pack.

Any thoughts out there??

                                                  The Slab Bacon

[Vortex Joe - N3IBX]

Here is a thought that I always pondered. I wonder if anyone out there ever stacked any of those high capacity "flat pack" batteries that they used to use in the film and battery packs for stuff like Polaroid cameras and the like. Those batteries were fairly high in voltage and current capacity, and quite thin. I often pondered that stacking them would make strapping but compact "B" battery pack.

Any thoughts out there??

                                                  The Slab Bacon

Frank,
        I wish I had a stack of old polaroid film batteries, I'd give it a try. I wonder what the battery voltage was for each pack of film? It almost seems a shame to have thrown the old holder away when it contained a perfectly good battery in it!

[Vortex Joe - N3IBX]

it would be really cool to run a trf on 160.  if? what's a if?

An IF is the frequency you have your TRF tuned to in order to drive your Silver-Marshall, "Aero", or whatever shortwave converter!

TRF-IF + SW converter = SW superheterodyne