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NTE Transistors for AU-9500?

awise1961

awise1961

Super Member
I have recapped my AU-9500 with Elna Silmic II's, and now I am planning to change out some flaky transistors on the Tone Board (2019).
I find that NTE has cross references and local stock of the following:

2SK30 = NTE 459, however somone on AK had used NTE458's and are they a better choice?

2SA726R = NTE 234 however, AK'rs recommended Fairchild KSA992FTA's, but will the NTE 234's be OK?

2SC1313R = NTE 199, however AK'rs recommended Fairchild KSC1845FTA's, but again I can get the NTE 199's locally.

2SC634A = NTE 85, however AK'rs recommended BC546B, and as with the others the NTE 85's are local.

Has anyone used these NTE's and are they good quality replacements?

Thanks, Al. Wise
 
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Most of us recoil in horror when someone mentions using NTE (or SK or REL or other cross reference parts). However, most of them are as good as the originals, and are often identical, especially small signal transistors. I would only stay away from them for very specialized or high power uses - unfortunately I can't give any feed back around the transistors mentioned. So YMMV. Good luck with it. my 2cents
 
Thanks sregor.

I purposely stayed away from NTE for the capacitors, but I am wondering if the transistors are OK.
 
The Fairchilds are very good transistors from my experience.
Those two replacements 992 1845 are good quality.
For the nte 85 just use any small signal transistor c945 etc.

NTE gets their parts from many suppliers and you are never sure what you are buying.
Plus their prices usually are about 4 to 5 times higher than from another suppplier.
Mouser is my personal favorite but Digikey and others are also highly thought of by many.

I know it's a pain to pay shipping on small orders but when quality is important sometimes worth it.
 
Thanks detailman.
I may use the NTE's to flush out the problem component and then replace them with the Fairchilds when they come in.
I hate paying $ 20.00 2-day expedited shipping on a $ 5.00 order.

Al. Wise
 
I've been ordering from mouser for 2 years and use standard shipping. Never had a shipment take more than 3 days total (NMT 70 hours) from time of ordering. Before I found Mouser and $.05 -$.20 transistors it was NTE's at the local ET Shop. Figured I spent $110.00 in transistors to redo a GX-365. I priced it all out @ mouser later and found WITH shipping it would have been $17.00 and I would have gotten better quality parts to boot. I don't recommend NTE unless it's a LAST RESORT and they are the only one's with the part.

Larry
 
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I found the answer myself this evening. I located the source of the unit's left channel novas/bursts to TR711 on the Tone Board (2019) by spraying each transistor with Radio Shack Cooler Spray. I replaced the offending 2SC1313R transistor (there is a crack in the case) with the NTE199 that was specified as a cross reference. The Novas/Bursts were replaced by a steady static through the left channel. I had a second NTE199 and decided to try another one in case the first was defective. The same steady static was present. At least there was consistancey. I replaced the second NTE199 with the original 2SC1313R and the static went away and the Novas/Bursts returned. The good news is that I have found the source of my AU-9500's problem. The bad news is that I will have to find the Fairchild replacments. Neither Mouser, nor Digikey has any in stock and it is many weeks to get them.
I could always look to salvage used parts from one of my other project receivers while I am waiting for Mouser and Digikey.

Al. Wise
 
Good testing devices if you're not sure it's fixed and the sacrificial NTE's were good "pulls" from a previous repair...have to qualify the only acceptable use of NTE devices...:D
 
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Hooray!

I found the Fairchild transistors at Mouser after all by calling them and simply changing how they are packaged (bulk instead of ammo on the 992's) and my parts will be here tomorrow. It's humorous that I bought 50 each of the 2KSA992FBU, 50 each of the 2KSC1845FTA, 50 each of the BC546B, and 50 of the N4148 diodes with Fed-X next day shipping for less than 20 each of the supposedly correct replacement NTE's cost locally.
Live and learn.


Al. Wise
 
awise1961 said:
Hooray!

I found the Fairchild transistors at Mouser after all by calling them and simply changing how they are packaged (bulk instead of ammo on the 992's) and my parts will be here tomorrow. It's humorous that I bought 50 each of the 2KSA992FBU, 50 each of the 2KSC1845FTA, 50 each of the BC546B, and 50 of the N4148 diodes with Fed-X next day shipping for less than 20 each of the supposedly correct replacement NTE's cost locally.
Live and learn.


Al. Wise
Click to expand...

Good follow up.
That's the point I was trying to make.
The 992 and 1845 truly are low noise transistors and work great in many applications.

Educational to see why many diy'ers hate shopping at the local retailers.
 
Fairchild transistors were installed on the 2019 board last night and the unit is running as it should. I'm working on burning in the new Elan Silmic II's.
Thanks for all of your help.
Now I need to recover from today's bonehead move on my TU-9500, but that is the subject for another thread. I have always said that I am a graduate from the school of hard knocks when it comes to working on electronics, but days like this make me think that I am working on my PHD in hard knocks.

Al. Wise
 
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