You will need to scour the net for the data sheets on thoes trannys down load the sheet then do several cross-references of 'like' components. Unless you are ultra hard-core and prefer to pay $40-up + S/H for hard to source obsolete components. I wish you the best of luck as it took me 3 days to find suitable replacements for my Pioneer SX-1500T using original Hitachi 2SD341's.
I am planning to replicate the same amps in this reciever as I had purchased it when I was 14 for a mere $35 that was..... well.... long ago in a land far away. (26 years ago).
I absolutely loved the way that reciever performed/sounded.
I was able to aquire the factory schematics a few years ago for free.
The best part was that the factory techs actually made notations on the schem's!
The only bummer is that the schem's are rev-b and my reciever is rev-c, a few adjustments and wire connections are different.
I am planning to replicate the same amps in this reciever as I had purchased it when I was 14 for a mere $35 that was..... well.... long ago in a land far away. (26 years ago).
I absolutely loved the way that reciever performed/sounded.
I was able to aquire the factory schematics a few years ago for free.
The best part was that the factory techs actually made notations on the schem's!
The only bummer is that the schem's are rev-b and my reciever is rev-c, a few adjustments and wire connections are different.
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Thanks for your quick reply. I've already started heading down that road. Think I'll be doing a lot of this sort of thing as I'll also be restoring a Sony TA-2000F, preamp, and a couple of Sony 3120A power amps to go with the Sony ST-5000FW tuner. Gave the stuff to my nephew back in 1970, and so far as I know, it's all non-operational, now. The price of nostalgia!
Yes. Funny. We're fine like that and we don't care if others think we like "old crap". Better than liking "new plastic junk".Ahh yes that funny word nostalgia. Then again we are all just funny people.
I wouldn't be surprised. New versions of old technology is better. It's like if they made fly-mo's today they would be awesome...As I recall my replacements happened to be ECG-something. It turns out the ECG's had better ratings.
Wouldn't they?
Funny how we all appreciate the old stuff because it's supposedely "better" and "lasts longer" than newer stuff, and then we often have to fix stuff like this. I guess it's still good because we have to fix this stuff thirty years later not replace it one year later(for today's stuff).
To get back to the topic at hand, I would not be exaggerating when I say that I have massive quantities of Germanium transistors.
What is the power dissipation that is required for that particular transistor? How much collector current? I even have a substitution manual form GE, I think, somewhere.
hint: look for member "2N1305" on a certain website called gearslutz...
Thanks, Guys
I'm going to do some serious probing in the ST-5000FW, starting tomorrow morning, but I'm going to have to find the manual for my Super Cricket, first. I'm afraid that I'm just an old "tube" guy trying to find my way through silicon jungle.
Fortunately, my problems with this tuner are in the power section, so with a little luck, I might just prevail. I'll be back on when I find exactly what I'll be needing.
I'm going to do some serious probing in the ST-5000FW, starting tomorrow morning, but I'm going to have to find the manual for my Super Cricket, first. I'm afraid that I'm just an old "tube" guy trying to find my way through silicon jungle.
Fortunately, my problems with this tuner are in the power section, so with a little luck, I might just prevail. I'll be back on when I find exactly what I'll be needing.
what's a "super cricket"?
Oh, don't worry, you will... Transistors are Kraft dinner compared to most tube circuits... At least coming from someone who knows both (okay I'm solid-state, first!)
It's a Sencore product, TF46, Transistor and FET tester, and it seems to work very well. Occasionally, it will report a good transistor as "bad", but will reverse itself when the transistor is tested again, "out-of-circuit".
Looks like the problem with the power supply, on my Sony ST-5000FW, tuner is going to turn out to be a series of bad capacitors. The four caps, that are wired in parallel with each leg of the full wave bridge, had all leaked and the legs, coming out of the leaking ends, corroded to the point that they were no longer connected to the board.
Have never seen caps exactly like these in question. they were marked ".o1M 100V MCC"
and are about 3/16" in diameter and 1/2" long, with leads that are about half the diameter of those found on 1/4 watt resistors.
There is also a 220 mfd, 50v cap that has leaked badly. And finally, there are a couple 1T243 diodes that test as "open". As soon as I can get down to San Diego, I should be able pick up the parts and be back in business.
Looks like the problem with the power supply, on my Sony ST-5000FW, tuner is going to turn out to be a series of bad capacitors. The four caps, that are wired in parallel with each leg of the full wave bridge, had all leaked and the legs, coming out of the leaking ends, corroded to the point that they were no longer connected to the board.
Have never seen caps exactly like these in question. they were marked ".o1M 100V MCC"
and are about 3/16" in diameter and 1/2" long, with leads that are about half the diameter of those found on 1/4 watt resistors.
There is also a 220 mfd, 50v cap that has leaked badly. And finally, there are a couple 1T243 diodes that test as "open". As soon as I can get down to San Diego, I should be able pick up the parts and be back in business.
Thank you for the info! Sencore, very good stuff. If you keep the switches clean (as with any old electronic equipment, unless it used sealed switches).
Capacitors, yes, I am surprised I didn't suggest that in the first place. Although ceramics (like the ones you were describing) rarely go bad. I have a box of vintage, military-grade components at my place and if I have time I 'll go through it, there were a bunch of leaded components (hopefully also containing a little bit of lead!) in which I can surely find some capacitors of that value.
cheers and happy new year,
Gain-wire
Capacitors, yes, I am surprised I didn't suggest that in the first place. Although ceramics (like the ones you were describing) rarely go bad. I have a box of vintage, military-grade components at my place and if I have time I 'll go through it, there were a bunch of leaded components (hopefully also containing a little bit of lead!) in which I can surely find some capacitors of that value.
cheers and happy new year,
Gain-wire
I'm assuming an exact "ceramic" replacement would not be necessary, but I may be able to run a few of them down, tomorrow.
Another anomaly I ran into is that Sony describes a Germanium diode in their parts list as a "1T240", but uses a "1T243" in the set. NTE calls for a NTE109, Germanium Fast Switching General purpose diode to replace the 1T240, and a NTE177, General Purpose Silicon Rectifier to replace the "1T243" Both have axial leads, but Sony uses a component labeled as a "1T243" and it has three leads, two of which are tied together in application. It, of course is a molded case device.
Go figure....
Another anomaly I ran into is that Sony describes a Germanium diode in their parts list as a "1T240", but uses a "1T243" in the set. NTE calls for a NTE109, Germanium Fast Switching General purpose diode to replace the 1T240, and a NTE177, General Purpose Silicon Rectifier to replace the "1T243" Both have axial leads, but Sony uses a component labeled as a "1T243" and it has three leads, two of which are tied together in application. It, of course is a molded case device.
Go figure....
Well, I guess that you might have a different version(in other words, revised) of the circuit, probably a better one. Unless it's a version that was revised in order to save costs. I know the fact that the 1T243 having three legs and the 1T240 having two is weird, but you'll still be able to retrofit the two legged, NTE177 version in there somehow.
Now, is there a possibility that the diodes could have been replaced in the past?
Anyway, I noticed, looking at the datasheets for both devices, which I don't know if you noticed, are written in different formats (the characteristics are not in the same order), that the Forward current for the NTE177 is lower than the NTE109. NTE177 is 60mA (they call it Continuous average current) and the NTE177 is 250mA (they call it simply average forward current).
I would choose the beefier version, the NTE177. There is no doubt a lot more than 60mA draw on each diode pair in the bridge, at all times.
How about a picture or two?
Now, is there a possibility that the diodes could have been replaced in the past?
Anyway, I noticed, looking at the datasheets for both devices, which I don't know if you noticed, are written in different formats (the characteristics are not in the same order), that the Forward current for the NTE177 is lower than the NTE109. NTE177 is 60mA (they call it Continuous average current) and the NTE177 is 250mA (they call it simply average forward current).
I would choose the beefier version, the NTE177. There is no doubt a lot more than 60mA draw on each diode pair in the bridge, at all times.
How about a picture or two?
What they did with the three-legged 1T243 is tie two of the legs together, so I'll be able to replace them with the standard variety without any problems. The failed pieces are encased in a rectangular block with one corner flattened. No idea what that particular configuration is called, but it is clearly labeled "1T243 N1". The leads are very thin, gold colored, flattened ribbons. The schematic shows the standard configuration.
As soon as I figure out how to attach a photo, I will shoot one to you. Failing that, it would be easy to attach a photo to your email, but I would need your address.
Henry
As soon as I figure out how to attach a photo, I will shoot one to you. Failing that, it would be easy to attach a photo to your email, but I would need your address.
Henry
The tuner is absolutely beautiful. Built in 1968 to go up against the "top-of-the-line" tuners of the day. I paid close to $500 dollars, in Hong Kong, in 1969, for just the FM tuner. Also bought a Sony TA-2000F, preamp, and two 3120A power amps, at the time. Ended up giving them all to my nephew a few years later. Of course, he trashed them all, over time, and I just bought them all back. Now, I'm on a mission to put them back into operation. Nostalgia can be expensive!
this is to increase the current drive capacity of the circuit.
It is usually known as a "Darlington" pair, when both transistors have the same polarity. If you have a PNP driving an NPN (or inversely) it is called, I believe, a quasi-complementary pair.
When these transistors were used in the sixties, darlington transistors had not yet come out, I think that they became available in the mid seventies, although I can't verify that truthfully...
Basically the gain (hfe) multiplies itself. The final current gain (in this case DC current gain) is the product of hfe X1 times hfe X2. Funny, they used to have the reference designator "X" for transistors...
Today a normal TO-220 transistor, or even a TO-18 could pass 0,5A with a hfe of about 100. But you still see this configuration in power supplies.
If you like I could send you an article about power supply design written in the seventies.
500$ in 1969? Holy cow, that was expensive!
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