Mr. Power Source

The 6.3v tube filament line on the tabletop Stromberg wasn't working so I acquired a replacement from eBay. The seller said it came from an electric organ and had been powering about 25 tubes, so it's more than beefy enough to light up the 14 or so in the radio. First I tested it at low voltage, mainly to see which end was which as there were no markings on the casing. I then hooked it up to the radio; there was a faint signal there briefly before a loud sputtering swamped it. The noise was unaffected by the volume control so I have to assume it is the fault once again of the power transformer, this time the high voltage line. This line goes directly to the rectifier tube, a 5U4G. I looked online for some circuit diagrams that include this tube to confirm what transformer I need to hunt down on eBay. On my travels I found this Japanese company's site which had some very good info, as well as a very charming explanation of a tube power amp:

"Mr. Amp is told like "Hey I am going to send you the audio signal" after the power is on to replay music. Mr. Power Source says "Ok then let's work! First I will make rice!" Mr. Amplifier says "The signal is small, so let's make it bigger". Then Mr. Output is like "Oh OK OK. Here I can shake Mr. Speaker by pulling out power! Here we go! Tada! Look! It's a good sound, isn't it?"

Shop

It's time once again to plug Duamuteffe's Etsy Store. No, there is nothing particularly Halloweeny on sale, unless you are dressing as a Pirate Queen and want a spiffy necklace of gold freshwater pearls. Since my last update there has been the inclusion of several jewelry pieces in addition to some more cute sock animals. The crystal earrings are particularly nice. Go and have a look!

Radio working

Thanks to a fresh shipment of parts, I have resurrected the aformentioned Star Roamer radio. I replaced the large electrolytic caps in the power supply section with nice modern ones which don't dry out. I also bypassed the old selenium rectifier in there, as although it was still rectifying, I read reports of them failing by releasing nasty fumes at you. The modern equivalent is a silicon diode, which can cost upwards of 4 cents each.

The other items that had stopped working since the 60s were all the slide switches that operate things like Auto Noise Limiting, On/Off etc. There were four of them, and they all had intermittant connections; it's weird why such a simple device would fail like this. Perhaps I'll autopsy one of them. Anyway, they still make them, and now it has four new ones.

I rigged up an antenna wire, made from old network cable, around the ceiling and switched on. After waiting a short while for the tubes to warm up I heard a light crackle. I had the band on AM and expected to get something, but the were no stations coming in. But when I switched to one of the three(!) shortwave bands I could hear all sorts of stuff; Canadian, South American, even Italian and Russian programs. I think I heard Chinese once. On later investigation, I found the problem with AM - there was a short on the tuning coil. So all I need to complete this radio now is a replacement signal strength meter, which was missing from the kit, and was probably used to fix another radio...

Animal Shop

Since she got a book about it, over the past few weeks Duamuteffe has been making cute animals from highly colored socks. We can't keep 'em all, so she set up an online store though Etsy. Go have a look; the pics are adorable:)

Radio update

A few weeks ago I was given a 60s shortwave radio kit. It is a Knight Kit Star Roamer and was partially assembled - I was tasked to finish it, and let the owner mess with it for a week or two. The instructions were very clear and 3/4 was done already; I just had to find a few spare capacitors and a diode (it was made at the time semiconductors were being introduced - vacuum tubes are still used for amplification). Unfortunately when I applied power, there was a loud 60Hz hum - I thought I could get away without replacing the electrolytics, but no...
In other radio news, the small Stromberg needs a new transformer (6v 10amp) and the big Stromberg needs at least one new 1/2 watt resistor. They didn't mess around with low power stuff in those days.

Big Radio

There is a small antique store down the road, and they had this radio at the back.


I put off buying it for a few weeks, but when we went in again I caved. It is a Stromberg Carlson Model 420 and I think I got a bargain. Most of that cabinet is solid wood, possibly maple. The four holes are where I took the knobs off; they were a little melty (old plastic), but I think I'll be able to get some repros. The insides were untouched, so there's a good chance it will work when it's been re-capped. I can't wait to see the special tuning indicator working - the hole in the centre of the dial houses an end-on tube that glows progressively greener when the signal is good!

Mouse

Mice come into our house occasionally, but they can't resist the peanut butter in our humane trap (basically a perspex box with a one-way lid).

It being 80 degrees during the day here, we decided to wait until late afternoon to go down the lake and get a bit of fishing in (it has been too long since August). While there, we released our peanutty friend. The funny thing was that once we got settled, our rods propped in Y-shaped sticks, we heard some rustling in the undergrowth next to us. It was Mr Mouse, cleaning himself up. Not really bothered too much about flash photography either, it seems!

Turtle

Nice, sunny weather at the mo so we went for a walk to the lake. On the way we found this little fellow on the grass verge next to a parking lot.



Although he was covered in mud, we could still see his bright orange underside and head stripes. We carried him to the lake and found him a nice rock pool out of the way. When we got back home we looked up what he was likely to be: current thoughts are towards him being a Painted Turtle.

Seasonal Weather

It was spring a couple of days ago; the brown grass was getting green and some crocuses had popped up their little heads. Then it started to snow, and has been for the past two days. We got about four inches and the roads had to be ploughed again. I was warned April was going to be varied in weather, but I didn't expect a mini winter. To be fair, this is apparently more snow than is normal, on average, for this part of the world, a part that seems to blame a lot of the weather on the "effect" of the lake. I'm sure there won't be any "lake effect" hurricanes, though.

New Old Radio

Yes, I got another one cheap off of eBay. This one had no back or power cord and was a little filthy from being in an attic. It can all be cleaned, though, and the circuit "re-capping" is already in progress by myself, the wood restoration is being handled by another dept (my wife). This one has an attractive roll-top to cover the dial when not in use, and apparently was portable - if you had a 90v battery! Some people say you could make one out of ten 9v, but I am not sure it is worth it. Will report again when I apply normal mains voltage.

Galactic

Because I participated in their first experiment, I just got an email announcing Galaxy Zoo 2. A while back, some astronomers set up a robot camera that surveyed the sky for galaxies, creating a huge picture database. They need them all to be classified; elliptical, spiral, mergers etc. It turns out that humans are still better than machines for this, so that is where the random People of the Web come in - yes, you too can be a scientist for half an hour. So I hereby encourage you to sign up and get classifying. No expertise req'd; just read the help, and don't worry about making mistakes as the same pic is shown to multiple people and some magical maths corrects all the errors.

Radio Update

After a bit of fiddling around, I'm getting a few faint stations from the poor old thing. There's still a fair amount of background noise, but at least this means that the tubes are still working. I cleaned the carbon tracks on the volume/tone variable resistors to reduce some of the crackling, and replaced some of the wires that connect the various in-cabinet aerials. I even made a makeshift secondary AM antenna using a spool of wire and a small square cardboard box, but the hissing remains. A bit of web-wandering revealed that there is a calibration procedure that can be done (someone had actually scanned-in some old Philco repair manuals). However, this is a fairly involved process and needs things like a signal generator, which I don't think I can lay my hands on at the mo. All-in-all I'm pleased with the result, and shall probably document my experiences and put them online in the near future.

Radio Times

Over the past few days I have been tinkering with an old 40s radio. I was mostly soldering in new wires where the old rubber ones had crumbled, and replacing the foil-and-paper capacitors (which are susceptible to moisture). Tonight I finally got to a stage where I could plug it in and try it:



The controls light up, which looks cool, but I'm only getting faint static at the moment. I'm very pleased that it actually turns on - that means the transformer is ok. Tomorrow I shall rig up an improvised aerial.

Ideas

Here is an interesting list of things to do with the "economic stimulus" money. My favorite is of course the Open Source software grants; and, as one of the comments says, this should be combined with a policy of a full adoption of open software for anything that is publicly funded - it's cheaper and historically more accessible. Plus more paid holiday time can't be bad.

Mmmmm

Today we tried out the Raj Mahal Indian Restaurant, which is apparently the only curry house in town at the moment. It was lunchtime so the buffet was in operation; an unusual (to me) "all-you-can-eat" arrangement. The food was lovely - a fair choice of beef, chicken and veg curries with rice and naan. For afters we had some aromatic Indian rice pudding and some of those sugar-coated fennel seeds. The guy we went with said it was unusually busy, but we didn't mind as that means business is good, and they will certainly get more business from us.