Restoring an Astor Porta GC Battery Radio (1939) using the Farm Radio PSU Part 2
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- เผยแพร่เมื่อ 25 ต.ค. 2024
- The Astor Porta has been sitting for over a year. Now that I have an appropriate PSU, it's time to see if this radio can sing again.
Schematic Link:
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For 1939 that is really in very nice condition. I was wondering about those boards that had the pins makes sense they were for the original battery pack. Well that wasn't to difficult you sorted that one out pretty quick Frank. Thanks for another great video.
Thanks Larry. I've got part 3 coming up soon dealing with the PSU again and trying to get that 1.5v circuit working. It's not looking promising lol
That’s a nice old set ! FWIW I used the exact same PS circuit on a Philco farm radio and had the same low filament volts issue. Since I only use the PS with one radio, I just used a trimmer resistor on the voltage regulator to dial in 1.45 V with the radio on. 1.6 V is a bit high. 2 D cells don’t last very long in my experience.
Hey, yes it is a nice old radio one you don't see very often. I have another scehmatic with a trimmer adjustment so I'm going to try that. Thanks for watching :)
I suggest using your DMM to measure the current drawn by the radio from each power supply (90V and 1.5V). That will help you to determine if 9V batteries could actually work, and also if there is a problem with your power supply on the 1.5V output. You can get a data sheet for a typical 9V battery from Eveready or Duracell, and probably many others. That will show how long the battery will last at different currents. You can also use power resistors and ohms law to load the 1.5V supply and see how much current it can put out, then decide if it's working properly.
Thanks for the info Man, very useful. As you know I'm a newbie with psu's and current/voltage draw. :)
That’s an interesting 🧐 little “brick” radio 📻. It looks 1940’s-ish. And real wood 🪵. The speaker 🔊 appears to be permanent magnet 🧲. Just make sure to replace the out of tolerance capacitors. Your friend, Jeff.
Caps all done Jeff. Yes it a great little radio :)
Has the year on the bottom of the radio
It's F code 1939
@@stevesavell128 Thanks Steve, I'll have a look
Nice radio. Surprised that the mustard caps needed changing as they are known to be reliable. I've only ever tested one that was out of spec (out of hundreds). Resistor drift was noteworthy!
Hey Adam, Thanks. I've read from many sources that the mustards are reliable but I figure when a component is 84 years old it's best to change it. Just my way of looking at things I suppose
@@exeterslab7781 Fair enough. I've just checked and they were introduced in 1958 so still pretty old! I think the resistors let this set down with their massive drift. Anyway I've subbed. Cheers
@@BrumAdam Thanks Man 😃
Nice Set !
Thanks Richard
Super!
My guess is that there is a capacitor between B+ and ground hiding somewhere that is partially shorted. You could check the HT current draw, probably under 10mA, if that is ok, then at least one of your 9v batteries is a dud. Are they alkalines? I don't think the mustards were around in 1939 and the speaker looks more recent, probably refurbished in th 50s or 60s. Good luck with the fault finding, it's a good little radio.
Hey Steve, I'll have another look but I'm pretty sure I've changed all the caps. Yeah, it never occurred to me that one of the batteries could be a dud and they are alkalines. I finished part 3 yesterday and did come up with a solution for the filament issue. Tell ya what, this project has been frustrating lol
I forgot to tell ya, if ya accidentally puncture a speaker 🔊 cone, it can be repaired with speaker 🔊 re-coning glue. Completely trashed 🗑️ speakers 🔊 can also be re-coned. That means ya can buy the speaker 🔊 re-coning kits, and the speaker 🔊 re-coning glue online. Ya put the new speaker 🔊 in the existing frame 🖼️ that the old one ☝️ was. Your friend, Jeff.
I must look into re-coning speakers properly one day. Thanks Jeff
@@exeterslab7781 Not to say that you’re doing it wrong 😑, but even I have had to improvise with things to get by. Your friend, Jeff.
@@jeffreyhickman3871 No offense taken Jeff, there are so many ways to do a single job and I like feedback that gives you new ideas into doing somthing
Apparently your "A" battery schematic doesn't supply enough current to get those tubes going on this particular radio.
That is due to bad resistors and old capacitors dragging down the power supply! Found a slightly better PSU.
Farm Radio Power Supply V1 by G. Forrest Cook to see how he has used the LM317 in the 1.5 Volt circuit. I actually
like the design better for both A and B supply as they can be both adjusted to compensate for some loading in the radio's
circuitry. You can modify the B supply to separate maximums like your PSU schematic using the Schottky diodes.
I just had a look at cook's schematic. I cant remember if I saw that before, as I've looked at so many lol. This is really giving me the shits Steve, but I'll persevere with it. Part 3 coming up in a day or two
Bummer Frank, so the 300Ma is not enough to power the radio heaters and the D cell batteries could be around 10,000 mAH each which work but not for very long because of the construction of the D cells. Perhaps you need at least 14 volts coming out of the transformer to double the .7 volts that you’re getting now or a bigger ampere transformer period.
Oh Ken, this is really trying my patience lol. I'll keep at it. It ain't gonna lick me (I hope)