Has anyone come up with any kind of fix for the problem with blown drivers in this radio? or replacement for RD16HHF1.
-
You can now help support WorldwideDX when you shop on Amazon at no additional cost to you! Simply follow this Shop on Amazon link first and a portion of any purchase is sent to WorldwideDX to help with site costs.
200GTL DX
- Thread starter Robalo
- Start date
ANy thing
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
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
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.
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.
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.
B
BOOTY MONSTER
Guest
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 .
im not saying they were high end radios , but he seem to do something right with them .
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.
Might try making a better board to chasis bondage session.
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.
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
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
Still having the AM power issue. It is actually 200w in both High and Low power.
I have replaced both VR9 and VR8 but no difference. I am guessing the power regulator stage for AM is the culprit.
Anyone have a Transistor voltage chart for the power Regulator ckt?
Roger
I have replaced both VR9 and VR8 but no difference. I am guessing the power regulator stage for AM is the culprit.
Anyone have a Transistor voltage chart for the power Regulator ckt?
Roger
Cobra 200GTL
I believe I have one of the last Cobra 200GTL sold. Five min after I got it one of the segments in the read out went dim, sent it in under warranty, Got it back, never have had any trouble with it since, very good radio, no drift, did add a Cobra power mike, friends say it sounds better than the stock mike I had on it The receive is a little low when I use it in the car, but works SUPER for a base station very happy with my Cobra 200 GTL...............Walterb
I believe I have one of the last Cobra 200GTL sold. Five min after I got it one of the segments in the read out went dim, sent it in under warranty, Got it back, never have had any trouble with it since, very good radio, no drift, did add a Cobra power mike, friends say it sounds better than the stock mike I had on it The receive is a little low when I use it in the car, but works SUPER for a base station very happy with my Cobra 200 GTL...............Walterb
examine any 5 chip resistors in this model, and at least one will show poor solder flow, and/or cracking on the pads. same applies to other components. extremely poor quality construction. the pots fail early. the driver is mounted with an overly thick insulator. solder splashes. screw hole thread coils hang from the chassis and intermittently short circuit points. tx audio on ssb is sharp and tinny. display dims on ssb tx.
this is by far THE WORST cb i have ever seen.
this is by far THE WORST cb i have ever seen.
then i would have to say the cobra 18wx runs a real close second, lol. but that's a whole other thread in itself.this is by far THE WORST cb i have ever seen.