2 radios killed because of static on antenna?

[montecarlossfan]

Well first of all I never had an issue using my radio equipment during a mild electrical storm until today. I had a 980ssb hooked up got a phone call , came back and went to tx ..no output..the radio was hotter than hell on the back..I thought to myself..power supply..checked it..13.8v. Put a cobra 200 on there...worked fine, was talking and then the guy across town goes ooh that was a good one, go to answer him..no tx. Hooked up a cobra 25 now....not an issue whatsoever the rest of the night.

I am wondering if the rd16hff1 transistors are so sensitive to static that they fry immediately. I know the 200gtl has it's issues with many people ..but the new uniden!!! This radio has been nothing but flowers for the past month running day and night....what gives.

Anyone else lose radios because of a storm in the area and not even a close strike? Or is it that junk rd16hhf1 mosfet?

 

[IMD262]

I've always considered it foolish to operate during a storm.If you can hear thunder, the storm is close enough to cause damage.

 

[ExitThirteen]

Those mosfets are junk. When I get into some extra cash, I'm going to purchase a 980, and swap it out with an IRF520N. Those RD16HHF1 Mosfets are real touchy, and are easily destroyed by SWR, being overdriven, or being over biased. I've had a few Cobra 200's come across my bench that had smoked RD16HHF1 mosfets in them, a couple were stock power, not even turned up. I ended up putting IRF520N's in them and sent them on their way.


However, it's odd that a 980 would have issues, perhaps they are sensitive to static from an antenna.


~Cheers~

 

[Robb]

Those mosfets are junk. When I get into some extra cash, I'm going to purchase a 980, and swap it out with an IRF520N. Those RD16HHF1 Mosfets are real touchy, and are easily destroyed by SWR, being overdriven, or being over biased. I've had a few Cobra 200's come across my bench that had smoked RD16HHF1 mosfets in them, a couple were stock power, not even turned up. I ended up putting IRF520N's in them and sent them on their way.


However, it's odd that a 980 would have issues, perhaps they are sensitive to static from an antenna.


~Cheers~

Curious; did you have to change out any parts to make the IRF520N work?

 

[montecarlossfan]

That is all I can think of right now is that they are very touchy , seems odd to me the 2 radios with that mosfet both die in the same night and it is a dead fet in the 200 as I checked it out...I go know that 2 legs have to be swapped as the rd16hhf1 has a weird layout.

 

[Robb]

Well MOSFETs are well-known to be very sensitive and easily damaged by static electricity.


EDIT:
Pic of the pinout of the RD16HHF1:

So the Drain and Source pins are reversed if a IRF520 is used?

 

[ExitThirteen]

Nope.

Altho MonteCarloSSfan is correct, 2 of the legs are swapped, so you have to be careful when installing the new IRF520N. Just make sure that your bias voltage is set about 3.7~3.8V at the gate, and your good. I haven't done a Cobra 200 in a while, so I don't remember offhand what the pinout is for the RD16HHF1, but you can Google it, I'm sure.


I DO know that those RD16HHF1's are just an awful mosfet, and I've never understood why Uniden would use a junk mosfet in such a good radio, other than to perhaps thwart people from tuning them up much past 12W output, since these mosfets go south REAL quick if you try to tune them up much.

I know the old bi-polar transistors are on their way out, but there's something to be said about a good C1969, C2312, and C1307 transistor.


~Cheers~

 

[9C1Driver]

Those mosfets are junk. When I get into some extra cash, I'm going to purchase a 980, and swap it out with an IRF520N. Those RD16HHF1 Mosfets are real touchy, and are easily destroyed by SWR, being overdriven, or being over biased. I've had a few Cobra 200's come across my bench that had smoked RD16HHF1 mosfets in them, a couple were stock power, not even turned up. I ended up putting IRF520N's in them and sent them on their way.


However, it's odd that a 980 would have issues, perhaps they are sensitive to static from an antenna.


~Cheers~

Just wondering, you start out by saying those mosfets are junk. And then your gonna swap them out with an IRF520. What would that be then, a junk for junk trade?

 

[Robb]

Nothing wrong with a IRF520N. Cheap, efficient, and plentiful. But it is still prone to failure if exposed to too much static electricity.

 

[Captain Kilowatt]

FET's are prone to failure due to static discharge but generally only until they are installed in a circuit. That is why they are stored in special conductive bags and require special grounding straps etc. while installing and handling them. Once they are installed in a circuit they are very much less susceptible to static discharge damage. I have to wonder if the real problem is the device itself or poor circuit design on the part of the manufacturer. MOSFET's have been used for a couple decades in commercial broadcast gear that is subject to taking direct lightning strikes without damage. Then again that gear has better circuit design than a CB radio which leads me back to my initial question of whether it is the fault of the device itself or the design of the circuit it is operating in.

 

[W5LZ]

The first thought that comes to mind is did you do any modification to that radio, any at all?
- 'Doc

 

[AudioShockwav]

Another question is, what kind of antenna are you running.
It is Always a good idea to unplug electronics when storms are in the area, all it takes is a near-by strike, it doesn't necessary have to hit your tower to cause damage.

I have to agree i have heard of quite a few of the RD16HHF1 devices going south.......


73
Jeff

 

[avistar23]

living in the carribbean we get vicious lightning, ive lost more flat screens, radios, antenna tuners, cableboxes, computers, routers, security camera dvr and a tv just last week you name it, ive lost it.

my towers have caused us to have 3 direct strikes, and ive had 3 before the towers, ive learnt, UNPLUG UNPLUG UNPLUG

my main ground network has seen its 3 number 4 wires melted in half off a direct striker. with newer often Chinese made electronics, it just do sent stand up to the test, for example my drake tuner took a direct strike and routed everything to ground, only burning up the ground tabs on the switch and the meter, at the same time saving my ft-847. just the other day i had a close strike, in between two of my towers, took out my q-see dvr, and an off brand flat screen, all my "quality electronics" were on. i feel there is a big difference in products being produced today, especially in extreme scenarios. the Chinese mass produced stuff is just made to work. not for long, not very well, just work.

i apologies for any errors or bad wording, my laptop screen is cracked and i can hardly see.

 

[TonyV225]

I know Im way late and miss the bus on this one but... Those fets are a huge problem and yes are prone to static failure!! I know several people that had this happen with Cobra 200 radios and a few other radios and remember you dont even need a storm to have static buildup. High winds can also do this I ran into this static buildup and it was bad if Ide hit my forearm on my tuner or better yet touch my pl-259 when disconnecting coax Ide get zapped every single time!!

I was talking to some guys on 75 meters on 3.913.00 and they explained what was happening. I then ran a few grounds to bleed off that static and no more problems with it. I was amazed how much static charge was actually in those coax lines and know that it was not good for the equipment aswell as me (getting zapped) Run a few grounds to bleed that static off

 

[montecarlossfan]

I hope it was just a fluke but for now, I'm going to say those mitsubishi devices are not the strongest....I have an imax 2000 on a tower and the whole thing is properly grounded, it must have just been the buildup of static due to lightning nearby. I know the sony icf 2000 i believe had the same issue and it happened when the unit was inside a house even. I'm going to try to convert the cobra to the irf520 and see how that holds up as those never gave me an issue.