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  #16  
Old 01-23-2017, 03:20 PM
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My childhood Arvin 446p used 2 zinc carbon cells in parallel to power filaments of a similar tube complement (3S4, 1U5, 1T4, 1R5) which seemed to work fine. Of course today I use Alkaline cells!

jr
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  #17  
Old 01-23-2017, 03:23 PM
old_coot88 old_coot88 is offline
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Outdated info deleted (paralleling zinc-carbon cells).

Last edited by old_coot88; 01-24-2017 at 07:47 PM. Reason: Outdated info.
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  #18  
Old 01-23-2017, 07:59 PM
dieseljeep dieseljeep is offline
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My childhood Arvin 446p used 2 zinc carbon cells in parallel to power filaments of a similar tube complement (3S4, 1U5, 1T4, 1R5) which seemed to work fine. Of course today I use Alkaline cells!

jr
The battery only portables seemed to have the filaments in parallel.
The so-called 3 way portables, AC/DC battery sets had the tube filaments in series in order to run them off the B+ supply using a large voltage dropping resistor, when operating off the power line.
The simpler designs used a 7.5 or 9 volt battery for the "A" supply, depending on the tube count. The more complicated designs used either 1.5 or 3 volt "A" supply. The power change over switching was more involved because the tube filaments had to be switched to series-parallel or parallel, plus having to take the cathode biasing into consideration.
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  #19  
Old 01-23-2017, 09:17 PM
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Originally Posted by old_coot88 View Post
Aha. L'arn something new every day. All the battery portables I ever serviced used the B+ dropper for the 50ma. filament string.

Actually the half-wave B+ supply is quite adequate for the low current requirement (no filament string to supply). The 'A' supply on the other hand, is full-wave with fairly massive filtering to deliver ripple-free current (at 100 ma in this design). Very snazzy and makes total sense.

If you felt like raising the B+ a bit, you could play with values of the voltage divider R13/R14.
Half-wave! That was the word I was looking for. I guess it all makes sense then.
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  #20  
Old 01-24-2017, 09:50 AM
dieseljeep dieseljeep is offline
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Way back, when I first started working on radios, the battery-only radios seemed to be around, free or very inexpensive. The electronic magazines had circuits for the "B" battery eliminator, but nothing for the "A" supply. Flashlite cells were inexpensive, so I built the "B" supplies and used the radio that way.
I always wondered why someone would buy a radio that cost that much to operate, when for a few bucks more, you could buy a radio that you could use year round. "B" batteries were always expensive.
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  #21  
Old 01-24-2017, 11:22 AM
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Way back, when I first started working on radios, the battery-only radios seemed to be around, free or very inexpensive. The electronic magazines had circuits for the "B" battery eliminator, but nothing for the "A" supply. Flashlite cells were inexpensive, so I built the "B" supplies and used the radio that way.
I always wondered why someone would buy a radio that cost that much to operate, when for a few bucks more, you could buy a radio that you could use year round. "B" batteries were always expensive.
I think safety was a concern... as a kid with a battery only tube radio, I was allowed to use it in the bathroom, with no fear of electrocution.

Design wise, elimination of the built in power supply, complex switching for the filament circuit, and space for cord storage allowed for a more compact design, which might have been a selling point.

The "B" batteries lasted pretty well compared to the much cheaper flashlight cells used for the "A" supply. IIRC, the 67 1/2 Volt battery was nearly 3 bucks in the 50s... nice birthday or xmas gift for a little kid.

jr
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  #22  
Old 01-24-2017, 01:57 PM
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Originally Posted by dieseljeep View Post
Way back, when I first started working on radios, the battery-only radios seemed to be around, free or very inexpensive. The electronic magazines had circuits for the "B" battery eliminator, but nothing for the "A" supply. Flashlite cells were inexpensive, so I built the "B" supplies and used the radio that way.
I always wondered why someone would buy a radio that cost that much to operate, when for a few bucks more, you could buy a radio that you could use year round. "B" batteries were always expensive.
Then there are the 'D' cell based DC-to-DC converters for portability and relatively cheap batteries....I was in the process of building one from plans from a 90's issue of ARC when I last moved....It worked but needed better filtering, shielding, and to be mounted in the period Zenith transoceanic battery shell I have...
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  #23  
Old 01-24-2017, 04:06 PM
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Unlike my vintage refrigerator, which has a neat inside door handle that still glows brightly in the dark. Ahh, delicious radioactive material all over my food.
That has to be a safety feature from shortly before the government mandated magnetic door handles.
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  #24  
Old 01-24-2017, 04:36 PM
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That has to be a safety feature from shortly before the government mandated magnetic door handles.
You mean magnetic door seals, right. If all fridges had inside escape handles they would not have had to go to magnets....

I've heard stories* of folks getting locked inside of old latching style fridges and suffocating or the like....

*From my mom in the 90's when in our old town we would see such fridges at the curb occasionally, and I was a dopey curious kid.
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  #25  
Old 01-24-2017, 10:53 PM
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Originally Posted by dieseljeep View Post
Way back, when I first started working on radios, the battery-only radios seemed to be around, free or very inexpensive. The electronic magazines had circuits for the "B" battery eliminator, but nothing for the "A" supply. Flashlite cells were inexpensive, so I built the "B" supplies and used the radio that way.
I always wondered why someone would buy a radio that cost that much to operate, when for a few bucks more, you could buy a radio that you could use year round. "B" batteries were always expensive.
So like... they'd sell you a kit to make a 67.5 v power supply, so that you could actually use the portable radio on plug-in power? Heh, but you still had to power the filaments with flashlight batteries? lol But hey, I guess the filament circuit is a lot more temperamental, probably would be an expensive kit that nobody would buy.

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That has to be a safety feature from shortly before the government mandated magnetic door handles.
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Originally Posted by Electronic M View Post
You mean magnetic door seals, right. If all fridges had inside escape handles they would not have had to go to magnets....

I've heard stories* of folks getting locked inside of old latching style fridges and suffocating or the like....

*From my mom in the 90's when in our old town we would see such fridges at the curb occasionally, and I was a dopey curious kid.
When I saw this, I had to buy this fridge.
I don't know for sure, but I think the reality of it was that the average mom just unreasonably worried that their child would be stupid enough AND go through the effort of removing all the food AND shelves so they could play hide and seek, hiding in the fridge - and Admiral thought it would make a nice selling feature to the concerned parent.

Last edited by MadMan; 01-24-2017 at 10:58 PM.
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  #26  
Old 01-27-2017, 10:25 AM
dieseljeep dieseljeep is offline
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So like... they'd sell you a kit to make a 67.5 v power supply, so that you could actually use the portable radio on plug-in power? Heh, but you still had to power the filaments with flashlight batteries? lol But hey, I guess the filament circuit is a lot more temperamental, probably would be an expensive kit that nobody would buy.






.
It wasn't a kit, it was a project in an electronics magazine. I bought the parts at Olsons and built it into a plastic box. It worked fine, but the radio became a hot chassis.
Back in the 1950's high capacitance, low voltage Electrolytics weren't that common, so it would be too costly to build an "A" supply with little or no hum.
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  #27  
Old 01-27-2017, 11:22 AM
dieseljeep dieseljeep is offline
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I wonder if someone smashed the clock when the alarm went off lol.

My clock also broke off the front cover. It has 4 protuding nubs that the screw go into, and all 4 were broken off AND the front cover was cracked almost in half. Happy to say that a lot of glue and elbow grease has fixed all that. Will do a post with pics of all the 'body work.'

And yeah, apparently the PSU's giant waxy cap is a common problem. I imagine it was a cheap capacitor even when it was made. Come to think of it, it's not even branded. The little waxy one in the radio was - 'Planet' - and that was probably ok.
I tried remounting the clock movement and it has to be the most crumbly plastic I ever seen! The bosses broke away from the contact assembly on the back of the clock. I drilled and used a 6/32 screw to remount it and the entire back cracked, when I tightened the screw and nut. I cleaned the clock knobs and installed them and one cracked in half when I turned it.
I'm leaving it the way it is! Like the letters GE mean: Good Enough!
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  #28  
Old 01-28-2017, 01:25 AM
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I tried remounting the clock movement and it has to be the most crumbly plastic I ever seen! The bosses broke away from the contact assembly on the back of the clock. I drilled and used a 6/32 screw to remount it and the entire back cracked, when I tightened the screw and nut. I cleaned the clock knobs and installed them and one cracked in half when I turned it.
I'm leaving it the way it is! Like the letters GE mean: Good Enough!
Dude tell me about it, this is the crappiest plastic ever. Literally touching my radio made it break in several more places, it was... aggravating. One thing broke, then another, and another. I'll rephrase my previous statement: it took a lot of glue, and a LOT of patience. In a way, I was kind of anticipating it all to fail in a spectacular pile of super-glue-glazed plastic chunks, but it all went together just fine. :3

Thanks for mailing that thingy btw.

(Vinyl still prefers her headphones.)

Last edited by MadMan; 01-28-2017 at 03:16 AM.
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  #29  
Old 02-28-2017, 07:39 PM
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Dude tell me about it, this is the crappiest plastic ever. Literally touching my radio made it break in several more places, it was... aggravating. One thing broke, then another, and another. I'll rephrase my previous statement: it took a lot of glue, and a LOT of patience. In a way, I was kind of anticipating it all to fail in a spectacular pile of super-glue-glazed plastic chunks, but it all went together just fine. :3

Thanks for mailing that thingy btw.

(Vinyl still prefers her headphones.)
The local antique mall near me has the clock part only from this particular clock radio, but the radio part is MIA so I'm guessing the radio failed but the clock still worked so the previous owner of the unit kept the clock and tossed the radio assembly. the clock part by the way is still in excellent shape yet with all of its knobs intact yet and everything. Perhaps you might consider coming over to Elkhart, Indiana over to an Antique Mall called 820 Antiques which is on 820 Ward Street just off of Beardsley Street, In Elkhart, Indiana.
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