I to am always skeptical of semiconductors from China. Glad to see you didn't get burned on this one. Have you ever used Eleflow transistors? I have been using them for a couple of years now and have never had a problem with anything from them. Pretty much any discontinued RF transistor you can think of is manufactured by them. I only have one problem with them, they don't have a US distributor. And also a suggestion. If your buying any type of quantity from them you can haggle them down on the price. I found that out on my first large order. Got a price quote on a fairly large order and said I would pass on a couple items due to price. Their reply was, well how about at this reduced price. Hmmmmmm, wasn't thinking, Chinese barter economy. From then on I always haggle the price with them. Mike
+MikesRadioRepair .CBRadio Hi Mike. I am a little cautious of buying from ebay let alone China lol. Just this time I got a good deal. Never bought from Eleflow but folks that have. Most gave positive reviews but one never got his part. Guess he did not push it hard enough.Thanks for stopping by and sharing that info.
I have the TS 2000, EVERYTHING, including ATU, Tranceiver, and power supply grounded, and when I check swr, use min pwr, which is 5 watts, keep 100% duty cycle modes like FM and AM power down, say to half-3/4, that way you will get long life out of your finals. ( Most times other end will hardly notice the difference between 50 watts & 100 Watts.) Great Radio, love it, Barry, VK2FP
It's always a gamble. Occasionally I will get an authentic one but many are fake.. You did all the right tests. They seem to go after audio transistors for amplifiers more than anything... Glad you lucked out!
I have verified that many Chinese transistors transmit at full power at 7MHz, but it decays as the frequency is raised. For example, at 7MHz we will get 100W, at 14MHz 95W, 24MHz 70W and 28MHz 50W. They should always be tested at the highest range of the transceiver. For example, some time ago I bought some MRF255 and the original reaches 50MHz. Well, in the entire HF band it has good performance, but it only provides 10W in 6 meters.
Hi Buddy, yeah always a problem with fake transistors. Great that this one is working. Is it possible to ask for the beta value? Otherwise you would end up with no matching finals.. Seems to be an interesting supplier.. Take care my friend. 73's
+TRXBench Hi Peter and thanks for dropping by. when I tested the beta of my good one it was 73 and the China part was 74. Both had a forward voltage of 567mv
I ran into the same problem you did and was forced to order outside of the country. But I could not complain; the price was right and I was able to get a critical piece of test equipment working again and put back on the bench.
I also have a problem on my TS 2000. I still not test it, but since he lost power on HF and VHF, my guess is the drivers. Another problem like this, to find good ones from China. But you had luck. Thanks for sharing.
Hi Buddy, on another video of yours you did a great job of explaining your train of thought/thought process on troubleshooting. What was your process in this case? You mentioned the unit was drawing a lot of power (I assume a lot of supply current). But then what? What made you go to the final amp, what testing?
Hi Patrick. Well, since the DC comes into the radio and is connected directly to the PA of the rig was the first clue. Also anything that pulls more than 1 amp has to be in the PA section. If something was shorted in the low power section it would burnt out before reaching the current limit this was drawing. With that said it led me straight to the amplifier. Hope that helps.
There are other parameters like thermal resistance junction to case which are very difficult to check. My guess is that transistor was NOS, not refurbished.
There is no such thing as a refurbished transistor as said in the video. You are correct on the thermal resistance. The suppliers gets old units and salvage parts from them, then resell the parts on en=bay as "refurbished".
3:52 side-by-side shot, shows that it's a counterfeit. The logo is a bit elongated on the copy, the fonts don't match and the etching is darker on the original. In most cases, the die is identical, but smaller. So don't expect the same output power and signal quality.
I agree it looks like a fake. But the Kenwood has been going strong at 105 watts output for nearly three years now. I did happen to find a set of these that a friend had bought many years ago. The beta is quite close to the originals. using a set of calipers they are the exact same size. Maybe the video causes them to look different. I tried the paint thinner test on the logo and it did not come off. Signal looks perfect on a spectrum analyzer. I bought several obsolete transistors from this seller and all checked out fine. Thanks for your comment.
a refurbished transistor is simply an old one removed from some old used equipment and then it's cleaned up re tinned and made to look like a brand new one again which is what you have in the photo, there's far to much tinning on the legs,it may well work ok but how long for ? this could have had 10 years use already,take a look at my channel for more tips on refurbished semiconductor.
+Ross DuClair Hi Ross. This is the DIY M12864 Graphics Version Transistor Tester Kit LCR ESR PWM You can look at video number 12 where I go through the assemble and test of it. Also there is links to the device.Thanks for watching.
+The Radio Shop : Thanks....I ordered two of them...I will try to use it as an in-circuit component tester as It "appears" that capacitors are tested using a frequency standard inside the tester.
Great, I like these units. Let me know what you think of them after a short time. I used this one as an in circuit tester and works good. Just make sure the caps are discharged.
Sorry to be ignorant but how do you "refurbish" a transistor. I understand semiconductors well and don't understand how something like that can be "refurbished". Any thoughts or links for edification?
Don, There is no such thing as "refurbished" transistors. This is just the way the Chinese list them. What they do is remove the transistors from junk boards, Clean all the solder off. They call it refurbished.
They are more like "Tested Used" transistors. It's mind boggling that such a common transistor is out or production and is no longer available (or not easily available) brand new.
They are more like "Tested Used" transistors. It's mind boggling that such a common transistor is out or production and is no longer available (or not easily available) brand new.
How can such a widely used power transistor be "no longer available" or at least not easily available? First, component producers create the demand, then they create the parts shortages (on purpose). A production facility could spit these transistors out like popcorn if they wanted to and it's not as if there isn't a demand out there for them. Ridiculous. Nice work, though!
Same thing happened to the SG500 amplifier for the SGC2020 radio. Transistors for the amp went NLA, out of production. Guess they tried going with Mosfets but nothing became of the project. Company kinda fell apart after the original owner died and his widow sold it off to one of the employees who decided to concentrate the company efforts on antennas and couplers for the military.
+mike charette Thanks for the comment. I never knew why when I order from China it took so long to get the part, but if it was in Hong Kong it was here in half the time. So I was thinking like you, Hong Kong is in China but why. Then I saw that video from Dave and it all cleared up.Thanks for watching.
It's a fake, look closely at how the lower numbers/letters line up with the larger upper ones. The old one, upper 5 and lower 0 line up as well as the upper 2 and lower A. The new unit... not so much. Other than that it's a pretty good reproduction and the curve trace showed it acceptable. Personally I got 4 fakes and ebay refunded my money. I still have the fakes and purchased some real ones at 10 times the price.
+Toe Knee Yep, really have to watch out for those fakes. Mr. Carlson's Lab recently put up a video with a lot of identifiers in it. Really big help.Thanks for watching.
