Need specs on Motorola RF transistor SS4153

[Th3_uN1Qu3]

I bought this transistor for $10 a couple years ago from a friend of mine. I'd been told at the time that it's a 40W VHF band transistor. It didn't work and i thought i got ripped off, but it turns out it needed to be fed more input power than my transmitter had at the time. The transistor looks kinda like this:


Just that under the Motorola logo it says SS4153 and under that 943. I was unable to find any info on it. What i do know is that it is a NPN RF power transistor (at least it acts like one), but i have no idea about its ratings, like maximum supply voltage, current and power output.

Now, i've thrown together a quick class C amplifier using it and it works when driven with 6W. Power supply for the whole transmitter is a switching brick of 20V and 2.5A and i tripped its protection several times in a row, so i would guess it currently outputs around 15-20W RF, given the typical 60-65% efficiency of RF bipolar transistors. I do not have an accurate RF power meter, and i left my 12 and 24v lightbulbs at a friends' house, so i can only tune for maximum output using my scope. I don't know what the output power actually is, but it's significantly less than 40W.
It is certainly above the 10W level though, as i have used trimmer capacitors like these, pulled out of a 5W 144MHz amplifier:
and they are getting very hot, it could certainly use better ones. I have mounted the transistor on a suitable heatsink with a fan on it. It runs fairly cool and the output signal is clean.

I would guess it is a 24 or 28 volt device but i'm not sure and i don't wanna blow it up. So if anyone has heard of this SS4153 transistor i would appreciate any data on it.

[ben7]

Re: Need specs on Motorola RF transistor SS4153

I found this, unfortunately, the link for the datasheet gives me a 404!
http://www.codingintl.com/ss4153-p-11880.html

Perhaps you might want to check some forums that are all about radios/RF equipment, they might have someone who knows what the specs are
Or perhaps you might want to contact motorola (or freescale, not sure if they bought motorola's semiconductor business or what...).

-Ben

[stj]

Re: Need specs on Motorola RF transistor SS4153

I found this, unfortunately, the link for the datasheet gives me a 404!
http://www.codingintl.com/ss4153-p-11880.html

Perhaps you might want to check some forums that are all about radios/RF equipment, they might have someone who knows what the specs are
Or perhaps you might want to contact motorola (or freescale, not sure if they bought motorola's semiconductor business or what...).

-Ben

maybe it's in the folder.
http://www.codingintl.com/pdf/datash...%20Transistor/

[ben7]

Re: Need specs on Motorola RF transistor SS4153

maybe it's in the folder.
http://www.codingintl.com/pdf/datash...%20Transistor/

Nope I don't see it in there.

[Th3_uN1Qu3]

Re: Need specs on Motorola RF transistor SS4153

Yeah i found the link as well. Doesn't actually contain the datasheet.

I contacted my friend who sold me this transistor and he told me he found it at that time (he's known to lie quite a bit, tho), and that it is 40W but it needs at least 15W input to get there, also that it should be powered with 24V and "not more than 5A".

That's pretty much in line with what i've figured out by its behavior so far, so i'll have to believe him. I'll report back with more info in the following weeks.

[kaboom]

Re: Need specs on Motorola RF transistor SS4153

Yeah i found the link as well. Doesn't actually contain the datasheet.

I contacted my friend who sold me this transistor and he told me he found it at that time (he's known to lie quite a bit, tho), and that it is 40W but it needs at least 15W input to get there, also that it should be powered with 24V and "not more than 5A".

That's pretty much in line with what i've figured out by its behavior so far, so i'll have to believe him. I'll report back with more info in the following weeks.

How are you matching/feeding it? You're getting less than a 5dB power gain.

[Th3_uN1Qu3]

Re: Need specs on Motorola RF transistor SS4153

Well the matching needs some work. I'll be buying a BLY89 transistor a couple days from now, that should give it enough input power.

Bipolar RF transistors of that vintage usually had 6-8dB gain, not any more. Only the japanese ones have 10dB. And don't get me started on the Russian-made KTxxx, those had like 4dB gain.

[kc8adu]

Re: Need specs on Motorola RF transistor SS4153

its likely house marked.most motorola rf bipolars are mrf-xxx.