It's time to reopen this old thread (again). I got around to replacing the two leaking 50uF 10V electrolytics on the board underside of my Magnavox AM-2 pocket transistor radio today with a couple of blue 47uF 25V electrolytics, and now the set is playing. There isn't all that much volume with this radio, but it's probably due to transistor leakage (since those particular transistors are really ancient). And yes, I did check the battery voltage while the set was playing, and it was stable at 4.5VDC.

John (xrhonda91): I didn't remove the board so I do not have a picture of the board top side.

Glad to see that you got it operational.

IIRC, there is at least one Electrolytic on the other side of the board. To get the most out it AFA volume and sensitivity, you need to replace all of the Electrolytics.

Thanks for the info Fifties. I was proceeding with absolute caution here (given the nostalgic value of this particular radio) as I certainly wasn't trying to replace (or check out) anything in this device that was absolutely necessary. I'll check out the other electrolytic(s) on the top side of the board too, and will report back with the results.

There are 4 on the schematic I have. 3 50 mfd, and one 10 mfd that goes straight to the volume control, which would be my candidate for low volume. I have done a bunch of replacements on radios of similar vintage, and the smaller the value, the more likely they seem to be to have completely dried out. Probably something like the ratio of surface area to volume being larger on the little guys, but whatever it is, you can almost guarantee all of the 3/5/10 mfd electrolytics are bad.The ones that connect to the center of the volume control pot being open is just like turning the volume all the way down.

Brett

Brett_Buck: That's a good bet. All of those electrolytics are dead as a door nail. Actually, there are (two 50uF 10V) electrolytics on the board top side, (two 50 uF 10V) electrolytics & (one 10uF 10V) electrolytic on the board underside. Looks like I'm going to have to pay another visit to my electronics distributor this week, and pick up the extra electrolytics.

John (xrhonda91): Enclosed is a scanned photo of the board top side that you were interested in.

I removed the speaker so the two silver 50uF 10V electrolytics on the board top side can be visible. They are both wired to a terminal strip underneath the speaker cone. The 10uF 10V silver electrolytic can be seen on a previous photo---it's horizontal to the two 50uF 10 V blue electrolytics.

There are a sum total of 5 electrolytics in this radio----two on the board top side & three on the board under side.

Hey Blustar1,

Haven't heard anything from you in a long while ! Thanks much for the excellent pics---sure like viewing that metal chassis & glad you've made progress... Is that a component lead sticking out of your speaker magnet dust cap ? If actually punctured and is contacting magnet surface, that would significantly reduce your audio level & quality by restricting cone movement !

As mentioned by Brett, I imagine that replacing audio coupling cap off of volume control will correct your low-volume "condition" if speaker okay...

Still sad to see "ZenithJim" on original post since he passed away awhile back without much notice... Seemed to be a really nice guy...

Be sure to let us know what happens when other caps replaced !

John

It's a pleasure talking to you again John. Yes, I regret to say that's a component lead that you see on the speaker cone. It must have picked one of those splinters up from the table, but I caught it a few moments after I took the photo. No, it didn't puncture the speaker cone, but it could have.

I picked up two additional 50uF 25V electrolytics and one 10uF 25V electrolytic from my local electronics distributor today. If I'm still awake when I arrive home before midnight, I'll replace the remaining caps at that time. Otherwise, Sunday will be the next window of opportunity for me to replace the remaining electrolytics.

Looking forward to seeing how it works with those last couple electrolytics replaced !

John

Hi John. I haven't yet replaced the three remaining electrolytics, but it's number one on my list. It's a six transistor radio, and there is some evidence that this radio was tinkered with before I acquired it. I'll be sure to report back with the results as soon as I'm done with the electrolytics.

Well, it's finally Sunday, and I got around to replacing the three remaining electrolytics on my Magnavox AM-2 radio. It has full volume now, and it plays great. Thanks everybody for your contributions. Enclosed is a scanned photo of the board top side. One can see the new black 10uF 25V electrolytic for the volume control that's located horizontally to the other two new electrolytics.

I wonder what a radio like this would be worth now that it's working?

Hey Blustar 1---thats great you got 'er goin' ! As good as that radio looks & with the hand-wired metal chassis, would think it be a really desirable set---but have no idea of current worth...

Did you keep your old caps just in case a future buyer might want it original ? I have a drawer section full of baggies with mine as you just never know...

John

Hi John. Yes, I still have the old electrolytics. After listening to some nice vintage music on this radio, it's sad that the manufacture of these radios ultimately went to foreigners.

Nicely done BlueStar!

We've discussed prices for old transistor radios in the past.
Collectors seem to be more interested in how a set displays,
rather than if it works or not. The general consensus is that
a working radio adds an additional 10% in price, which doesn't
seem fair to me.

Checking completed eBay listings for your radio is probably
the best way to determine a fair market value.

AFA foreign manufacturing of transistor radios... we've been outsourcing
assembly of these little guys for nearly 50 years! IIRC by about 1964,
there were no American-made transistor radios produced.

Pretty sad.

~ Mitch ~

Good neat job there, BlueStar1. It's always that last Electrolytic that does the trick for maximum bang.

The Bunis Guide suggests but a 10% bump in the value of an operating Transistor set, the same as PBPP pointed out.


I received a Japanese "Jupiter" six Transistor radio as a gift in 1958 (which I still have), and it still works with the original 'lytics, albeit with reduced volume. They were the ones to have, with their smaller sizes, superior looks, and obviously excellent build quality.

Fifties wrote: "I received a Japanese "Jupiter" six Transistor radio as a gift in 1958 (which I still have), and it still works with the original 'lytics, albeit with reduced volume. They were the ones to have, with their smaller sizes, superior looks, and obviously excellent build quality."


Yes, and those early transistor radios sure played nice.

Yeah!!! I happened to finally locate the leather carrying case for the Magnavox AM-2 transistor radio today that was surprisingly still tucked away upstairs. The leather case is in nice condition, but the carrying strap is broken in several places. Well, at least I now have the case, and that should add to the radio's value even more.

I've been taking my Magnavox AM-2 out in the back yard almost every day for several weeks, and have been playing it for hours at a time. It seems to play forever on one of those EN133A 4.5 VDC alkaline batteries as I haven't even replaced the first battery yet. That radio is a nice performer!

Be careful with that great radio---don't think I'd let one as nice as yours out of the house !

Good to hear about the battery---wonder how long it will actually last ? Keep an eye open for any seepage/leakage !

John

On one of those EN133A batteries, the radio has been playing for hours, hours and hours. I suppose that I will eventually have to replace the battery. Moreover, I do periodically check the battery for leakage, and it's still in good shape.