12AV6-12CS6 Transmitter(Revised Schematic)

Blustar1 · **Joined:** Jan Mon 04, 2010 2:52 am **Posts:** 681

http://www.ebay.com/itm/VACUUM-TUBE-12C ... 35a5b5d01d

Larry: One NOS 12CS6 tube is currently up for auction on eBay for $4.95 & $2.75 shipping. See the above link.

Mike3 · **Posted:** Feb Wed 22, 2012 4:16 pm

You can also try thsi ebay seller.....

http://www.ebay.com/itm/130290359493?ss ... 2076wt_905

scroll down to see what tubes he has for sale.. and his other auctions.. I bought my 12cs6 and 12av6 for $1 , $2... 6.00 shipping .. you can order many tubes for the same 6.00 shipping...

Mike

35Z5 · **Posted:** Feb Wed 22, 2012 7:12 pm

Many of the suppliers have 12CS6 for a buck... I've mostly bought my cheap tubes from ESRC but Stan has a 10 piece minimum for the $1 specials...

Didn't see anything about a minimum here...

http://www.vacuumtubes.net/prices.htm

rocketeer · **Posted:** Feb Wed 22, 2012 8:40 pm

Thanks everybody. I updated the list.

Larry

Flipperhome · **Posted:** Feb Wed 22, 2012 9:50 pm

35Z5 wrote:

Many of the suppliers have 12CS6 for a buck... I've mostly bought my cheap tubes from ESRC but Stan has a 10 piece minimum for the $1 specials...

Didn't see anything about a minimum here...

http://www.vacuumtubes.net/prices.htm

Nice catch and, by golly, I had forgotten about that one because, at the time, they were a tad more expensive on the tubes I was looking for. For example, their 6AU7, 45B5, and 20EZ7 prices are $5 vs $4 at ABCvacuumtubes. That's not a 'universal truth', though, because they're 2 bucks for the 7AU7 vs $3 at ABC.

At first blush it looks like they don't do "dollar days" (which, btw, is always there and, as far as I can tell, always the same) but they just don't provide a consolidated list of '1 buck' tubes and checking 10 or so types from the ABCvacuumtubes "dollar days" list came up as 1 buck in their numerical listing as well.

So, for a couple of 1 buck tubes, they might be a better deal, depending on what their shipping cost is.

Blustar1 · **Joined:** Jan Mon 04, 2010 2:52 am **Posts:** 681

Flipperhome wrote: "So, for a couple of 1 buck tubes, they might be a better deal, depending on what their shipping cost is".

There's the catch 22: The shipping cost. They're not too up front about that.

Flipperhome · **Posted:** Feb Thu 23, 2012 7:18 am

Blustar1 wrote:

There's the catch 22: The shipping cost. They're not too up front about that.

Yes, that's why I put the heads up in there. But they do have an 800 number so if one is inclined to give them a try I'd suggest phoning it in rather than the online form with maybe a 'surprise' when the shipping is added.

They do say their policy is "Don't try to make money by charging the customer inflated shipping costs," though.

bill hamre · **Posted:** Feb Thu 23, 2012 5:11 pm

D1, D2, D3 - 1N4007
--------------------------------
They were included with your kit

rocketeer · **Posted:** Feb Thu 23, 2012 5:50 pm

bill hamre wrote:

D1, D2, D3 - 1N4007
--------------------------------
They were included with your kit

You're right, they had fallen off the paper and were laying in the box. I hadn't notice them before. :oops:

Larry

bill hamre · **Posted:** Feb Thu 23, 2012 6:14 pm

My fault - should have been taped on

rocketeer · **Posted:** Feb Sat 25, 2012 10:55 pm

Well it looks like I finally have all the parts so no more excuses, time to get off the pot. Lemme know if anybody smells smoke. :wink:

Larry

35Z5 · **Posted:** Feb Sun 26, 2012 12:25 am

The smoke isn't packed very tightly in the 36v transformer winding... Yeah some of mine escaped when I decided B+ on the PCB was ground(so much for memory), doesn't seem to be any worse for the wear though..

Till your sure all is OK, it isn't a bad idea to bring it up on a variac, or use a dim bulb tester... In the original design, there won't be much if any 5v supply for the osc unless the tubes are warmed & drawing current...

Tom

rocketeer · **Posted:** Feb Tue 28, 2012 12:54 am

The case is put together and the innards are layed out and mounts drilled. The PCB is roughed in but nothing is soldered or wired yet. Over the next few days I will go over the PCB a couple more times just to be sure before I start soldering, I've never done freestyle SS before. Anything look out of whack?

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Larry

bill hamre · **Posted:** Feb Tue 28, 2012 12:59 am

Nice start Larry. Glad you finally gathered all parts. Normally I'm a bigger help with parts than this time.

Blustar1 · **Joined:** Jan Mon 04, 2010 2:52 am **Posts:** 681

It's looking good Larry. Nice work!

rocketeer · **Posted:** Mar Mon 12, 2012 3:34 am

Time for an update I guess. I accidentally fried the LM7805 so I set the xmitter aside for a few days until I could get to an RS and get a replacement. As sometimes happens I got tangled up with another project (still not resolved) and time passed. Yesterday I needed to drive to town so I finally got a new LM7805. I just soldered it in and, surprise, no magic smoke! I'm finally getting the correct voltage at the crystal so tomorrow I'll start in on wiring the MP3 player into the circuit. Fingers crossed!

Larry

bill hamre · **Posted:** Mar Mon 12, 2012 3:39 pm

Magic smoke is the most important part of homebrewing.

35Z5 · **Posted:** Mar Mon 12, 2012 3:49 pm

Watch running the LM7805 without a load as input will be high, causing it to over heat... Without the Mp3 player attached hang some resistance to ground, 25ma or so should be OK...

Tom

bill hamre · **Posted:** Mar Mon 12, 2012 3:53 pm

I'm leaving for a two week vacation on Friday. So, if any one needs parts or kits let me know now.

rocketeer · **Posted:** Mar Tue 13, 2012 2:43 am

It's alive!

The MP3 player, so far, works like a champ. My daily driver quit on me today so I'm not testing it under ideal conditions. Tomorrow I'll try some different recordings and a couple of different receivers to get a better idea. Thanks to everybody for their help. Now that I've gone through this one time I have a better idea of what I'm doing so I'm thinking of building another; one I won't be ashamed to show people what it looks like under the hood.

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Larry

12AV6-12CS6 Transmitter(Revised Schematic)

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