[Chuck Schwark]

Bill,

Mr. Schwark was my Dad.... I'm just Chuck.

[batterymaker]

Okay....Chuck

I just finished taking measurements off of it and applying the numbers in my "cookbook." It's all boxed up and ready to ship. I'll be sending it either Monday or Tuesday.

Bill

[Chuck Schwark]

Looking forward to "playing" with it. Thanks Bill.

[Chuck Schwark]

Ok - here we go Bill.

I love the prototype AB Mystery Pack.

[Image: http://www.philcorepairbench.com/images/newpack01.jpg]

Two things to tweek:

1. Thickness dimension. Needs to "snug" into the hold down tabs on the Mystery Control:

[Image: http://www.philcorepairbench.com/images/newpack02.jpg]

[Image: http://www.philcorepairbench.com/images/newpack03.jpg]

2. The socket need firmer contacts. The formed soft brass stock bends and looses contact with the Mystery Control battery plug pins too easily. Consider using salvaged tube socket contacts? The four socket contacts need to be springy stiff, if you know what I mean.

One another note. Loaded the pack with the 2 C cells and 5 9-volts and "warmed up" my intact Mystery Control that I had not tested since I got it. It sprang to life most adaquately. Here is a scope capture of the RF output at the plate of the #30 tube being held in the "ON" mode and not pulsing. As you can see, the peak-to-peak RF output is 60-70 volts. Plenty of punch in my book. I adjusted the variable cap to move the frequency around a bit. The cap has more range than the five Philco specified 350-400 kHz Mystery Control "channels," and seems to put out a very respectable sine-wave signal with a minimum of distortion.

[Image: http://www.philcorepairbench.com/images/...%20Wfm.jpg]

[batterymaker]

Okay--so the good news--it fits, can stand to be thicker.

Bad news--the spring brass is too thin to work properly. I'll see about upgrading to a thicker variety.

Other than that, it's working good, right?

Bill

[Chuck Schwark]

Connections are right on. Works fine. Only problem is the batteries eventually wear out and you have to replace them,

The height and width dimensions are perfect. It's a flush match with the original, except the "thickness," like I stated above.

BTW, I had to crimp the brass contacts around the plug pins once mated to make reliable contacts. After 2 or 3 in-out cycles, they tended to get intermittant.

Do you have a 4-prong battery plug to test with? If not, I can send one back with the prototype, de-soldered from my non-working unit.

I can also send back an actual battery pack socket found in the non-working unit someone had removed from a dead pack and soldered new-style battery jumpers onto it to mate with two newer (1950s) batteries.

[batterymaker]

I have a couple of originals--all I need to do is go up one grade thickness in my sheet brass, and it should be all set.

Since you've mentioned the battery can be thicker, I'm wondering if I can install D cells. I'll have to look into that.

So, now that it's operating, just how far can you be away from the receiver to send a command to it?


Bill

[Chuck Schwark]

Wish I had a mystery control set - I don't.

The specs say a reliable 25 ft. radius from the radio, with allowances for shielding metal piping, wall studs, large metal appliances, etc.

[batterymaker]

Sounds like that thing puts out a robust signal, then.

Well, Let me see what I can do about the thickness.

[Chuck Schwark]

Do you need this prototype back? Let me know, it's no problem...

[batterymaker]

Go ahead and keep it--you've helped me a great deal in figuring out the details.

Bill

[Chuck Schwark]

Well, thank you very kindy. You're very generous Bill.

I owe you some Philco service info when ever you need it - just ask.

When and if you go into production I will put a graphical link to you on my site with the batteries you offer, etc.

[batterymaker]

Just won an original pack off of the 'bay, so when it arrives, I'll be able to do real-time measurements with it. In a few weeks, I'll have one built and see how it fares on eBay.

So, I guess I should ask, how many of you are interested in purchasing this type of pack?

[Chuck Schwark]

Hi again,

Hope your Thanksgiving was good.

Since I already have the prototype, I only need one more. I'm sure you'll get "bites" from some people here and in the ARF forums and R+P newsgroup.

Happy Holidays

[Guest]

Chuck, this is the guy I thought was YOU making the new batteries. Beautiful work!!