Where Did All The Transistors Go?

[Yankee]

Does any company make a dual final TRANSISTOR radio anymore? I am so fed up with worthless FET's that I will never buy another radio with FET finals. I will go to the dark side and buy a 30 year old Yaesu first. All I want is a nice strong, long lasting radio with some 11 meter channel spread. Is that too much to ask?

It doesn't even have to be new. I look and look and read reviews and get down to the end of the article and they all boast of how strong their stinking FET's are. They lie. Is there any hope?

 

[GnG8d]

Nope, bipolar transistors are going the way of the dinosaur.

 

[Yankee]

How about older rigs? Somebody, sometime, had to make a radio with pills?

 

[Robb]

MOSFETs are OK until someone pushes them too high where they become unstable and fail. The upside is that they are plentiful and very, very cheap. Cheaper to replace than any bipolar transistor ever was before. The trick is, if you have a radio that has dual MOSFET transistors; then don't tune them up so high as to squeeze every last watt out of them. Sure they can do almost twice what a bipolar transistor can do. But they will just fail much quicker that way.

Many newer Ham radios use MOSFETs - BTW.

 

[GnG8d]

If you watch the money people spend on TV sweep tubes to keep old amps alive, that's how popular bjt's will look in the not to distant future. The only difference will be the knockoff Chinese transistors where the TV sweep tube just went extinct.

In reality now that I think of it, the 3-500z, 572b and others are Chinese knockoffs too, so maybe the Chinese will be able to fill the void for awhile once their Silicon Valley transformation is complete.

 

[Yankee]

Yes, I know how tender they are. They can't take any pressure. My question is, why put them in a radio, and NOT turn the radio down so they can NOT blow the FET's? This seems like an easy call to me. Poor design to make something that can ruin a radio by the inadvertent twist of a knob, heh?

And who said anything about new? LOL I have been leaning toward the Yaesu 101E or Kenwood TS 440s. I think you just made up my mind.

I have three pieces of equipment here with FET's that don't work. If it's OK, just take my word for it? I don't need to embarrass myself any further.

"the 3-500z, 572b and others are Chinese knockoffs too"
I believe I have read the Russians are making ceramic replacements for the 3-500z. Ceramic or metal. Can't beat tubes, anyone knows that.

 

[GnG8d]

Tinkering with older equipment is a large segment of the radio community, not a thing wrong with that.

 

[Yankee]

The truth is, I was pretty much already decided, but I needed a second opinion on the lack of pill final radios. I have heard a LOT of Yaesu and Kenwoods on 11 meters and they all sounded better than anything else on the air. I won't be disappointed. Tinkering with old is better than buying junk new from china.

 

[Robb]

Yes, I know how tender they are. They can't take any pressure. My question is, why put them in a radio, and NOT turn the radio down so they can NOT blow the FET's? This seems like an easy call to me. Poor design to make something that can ruin a radio by the inadvertent twist of a knob, heh?

And who said anything about new? LOL I have been leaning toward the Yaesu 101E or Kenwood TS 440s. I think you just made up my mind.

I have three pieces of equipment here with FET's that don't work. If it's OK, just take my word for it? I don't need to embarrass myself any further.

"the 3-500z, 572b and others are Chinese knockoffs too"
I believe I have read the Russians are making ceramic replacements for the 3-500z. Ceramic or metal. Can't beat tubes, anyone knows that.

No.
Example:
A Galaxy 99 w/2 bipolar transistors is rated at 35w PEP. A Galaxy 99v2 w/2 MOSFETs will work just fine and be quite stable at 40w PEP and probably not fail. But push the output up to 60 watts in the v2 and it will break quickly. That would be the shop/tune-up guy if he turned up the ALC and AMC output inside the radio to get those numbers.

So; do you blame the radio mfr, the MOSFET part, the operator, or shop/tune-up guy?
I blame the shop/tune-up guy, because he should have known better.

 

[Yankee]

A Galaxy 99v2 w/2 MOSFETs will work just fine and be quite stable at 35w PEP and probably not fail. But push the output up to 60 watts in the v2 and it will break quickly. That would be the operator's fault or the shop/tune-up guy

My point is, the radio should not be made so it CAN push the output to a point that it fails, not out of the factory box. I have amps here with pills I have by accident, over volted, over driven and over modulated, still going strong. And I have a few here with FET's that failed the first time I sneezed with my finger on the dial. Just saying.

 

[GnG8d]

The truth is, I was pretty much already decided, but I needed a second opinion on the lack of pill final radios. I have heard a LOT of Yaesu and Kenwoods on 11 meters and they all sounded better than anything else on the air. I won't be disappointed. Tinkering with old is better than buying junk new from china.

If each device is operated within spec you'll never hear the difference in audio between a tube, fet or bjt. Guitar guys are all about tubes because they distort the shit out of them and transistors don't do as well in that arena.

 

[GnG8d]

No.
Example:
A Galaxy 99 w/2 bipolar transistors is rated at 35w PEP. A Galaxy 99v2 w/2 MOSFETs will work just fine and be quite stable at 40w PEP and probably not fail. But push the output up to 60 watts in the v2 and it will break quickly. That would be the shop/tune-up guy if he turned up the ALC and AMC output inside the radio to get those numbers.

So; do you blame the mfr, the MOSFET part, or the operator, or shop/tune-up guy?
I blame the shop/tune-up guy, because he should have known better.

This is a slippery slope. Tuned circuits run cooler when properly tuned and produce more power out the pipe. So can the final PA handle the circuit driving them? I guess that's the question.

 

[Robb]

My point is, the radio should not be made so it CAN push the output to a point that it fails, not out of the factory box. I have amps here with pills I have by accident, over volted, over driven and over modulated, still going strong. And I have a few here with FET's that failed the first time I sneezed with my finger on the dial. Just saying.

OK.
But here is yet another well-known example:

The new Ranger 2970N2 is a great example. We had some members on this forum buy a "tweaked 'n peaked" version of this radio, and all of these radios were just dropping like flies. This shop ('nameless') was advertising some 300w from a 200w/OEM radio that had MOSFETs.

People ended up sending their radios to Doug's Custom CB and other shops to de-tune and fix the radios back to OEM specs. No more problems with the radio after that. So long as the reputable shops didn't push the finals where they were unstable at that output level, the radio did fine. Better shops knew much better than to do that to a MOSFET radio; the shops that didn't know any better are well known and should be avoided for reasons that are all-too-obvious now.

It was a real fiasco for those who tried to get the shop who modded these radio to own up to their mistakes. Those shops even tried to make the cost of repair higher than the cost of buying the radio new in order to cover their own azz. Just because they thought they could sell a radio that could put out more watts than another shop would. Kinda proved they didn't know what they were doing in the first place.

Just sayin - is all . .

 

[Mudfoot]

@Robb...

When did we start being polite by not naming shops that torque on radios?

 

[GnG8d]

@Robb...

When did we start being polite by not naming shops that torque on radios?

Those shops aren't tuning radios apparently, they are jacking with bias and traps to make watts show up on a meter.

A properly tuned radio runs cooler and makes more power than an ill tuned radio. But making fake watts produces more heat and is ill tuned.