200GTL DX - Worldwide DX Amateur Radio Forums - Ham - CB - HF - VHF

Robalo · #1 (**permalink**) 09-08-2008, 10:28 PM

Has anyone come up with any kind of fix for the problem with blown drivers in this radio? or replacement for RD16HHF1.

Rogerbird1 · #2 (**permalink**) 11-02-2008, 01:13 PM

Hello,
I am wondering what I am doing wrong..
I have a 200 with a blown driver, (2nd time) It is now out of warranty, and the last time it was repaired in warranty.

This time I have replaced the RD16hhf1 and performed the Driver Bias adj.
SSB operates normally 10w/40w but,
AM draws 15A and Pegs my Wattmeter (excess of 100w) in either low or Hi power.
I have adj the bias to 60ma / 1.2A as in the service manual. I have tried reducing the
ma to 20ma / 200ma and it does the same.
I havent scoped it yet, but I imagine it is Oscillating to give such a false reading.

Did I miss a step, or is something else pooched?

Roger

Pilsener · #3 (**permalink**) 11-23-2008, 03:06 PM

There is no replacement for the RD16HHF.

And, sadly enough, these radios are known to be a huge piece of s**t.
So this failure is not a unique case.

I have one myself, which blew both the driver and the finals, for no obvious reason, but I haven't dared to use it after it was fixed.
Guess it just would blow again in a while.

I bought a Magnum instead, and put the Cobra way back in the closet.

Cheech · #4 (**permalink**) 11-24-2008, 08:18 PM

I have blown the driver out in my radio three times and every time it was a result of a thunder storm. These drivers are static sensitive. If your running one on a fiberglass base antenna your more likely to blow the driver. I have not had another one blow sense I switched over to my maco V5000. If it was not for that driver I would have had no problems with my radio. I also do not recommend turning the power up to high on these radios because they do not have a big enough heat sink. 100 Watts pep on AM and SSB is plenty. If I remember right there was also people having trouble with the heat frying the drivers.

BOOTY MONSTER · #5 (**permalink**) 11-25-2008, 05:54 AM

id contact DTB about it . he seems to be the only one that sold those radios without getting a ton of grief back about them . he would do ALL the updates befor he let them out the door .
im not saying they were high end radios , but he seem to do something right with them .

jazzsinger · #6 (**permalink**) 11-29-2008, 07:30 PM

Ultimate cobra 200 mod!!!

DIRTYWHITEBOY · #7 (**permalink**) 11-29-2008, 07:36 PM

Quote:

Originally Posted by jazzsinger

Ultimate cobra 200 mod!!!

HAHAHAHAHAHAHAHAHAHAHAHAHA

mackmobile43 · #8 (**permalink**) 11-29-2008, 07:44 PM

Has anyone ever considered that placing the RD16HHF1 that close to the final rf stage may cause rf to cause it to go open circuit and then a host of other catostrophic anomolies.

Might try making a better board to chasis bondage session.

junon600 · #9 (**permalink**) 12-10-2008, 06:42 PM

Jazz has found the best mod for these boat anchors. I always wondered how they could be made better. This seems the best way. Right in the can.

ExitThirteen · #10 (**permalink**) 12-16-2008, 10:12 AM

I did a cross-reference on a RD16HHF1 driver, and it's a 16W mosfet.

I wouldn't mind getting a 200GTL with a blown driver and tinkering with it... might be a way to put in a good old IRF520N mosfet instead. Would just have to make sure the biasing is correct.

Anyone have a 200GTL they'd sell cheap that's got a blown driver? If I got it working with a IRF520N I'd post the results on the forums.

Anyhow, it's just a thought, being as the RD16HHF1 and IRF520N are both mosfets, I don't see why the potential wouldn't be there for an IRF520N replacement of the RD16HHF1. At worst, you might have to swap a couple legs when installing the IRF520N because the pinouts might not be the same.

Just my 2cents worth.

-Exit