rigmo wrote:

Electronically wrote: ↑Sun May 03, 2020 10:40 am Try the chips nrg mentioned you'll be surprised at how well those chips work.youll find you'll have less issues if inserted into one of those boards. So forget about mrf186 and 9180.

Tru but can you named specify?
In one of hand I cant because if all good with match and tune working perfectly.. cost 35usd... in diy kit...

rigmo wrote: ↑Sun May 03, 2020 8:08 pm 130usd,,,, foe 150W forget... for 90$ you can get 500 600w

TGillies wrote:I wasted 3 of those MRF chips on the same board, tried both MRF9180 & MRF186. had the exact same problem as you at first, it would only give me reduced power before blowing altogether. i came to the conclusion it was the board itself.

viewtopic.php?f=11&t=2319&p=25632#p25632

gotta watch for some of these chinese parts, they can be very temperamental, yet other times solid... from my experience anyway.

TGillies wrote: ↑Mon May 11, 2020 1:40 am I wasted 3 of those MRF chips on the same board, tried both MRF9180 & MRF186. had the exact same problem as you at first, it would only give me reduced power before blowing altogether. i came to the conclusion it was the board itself.

viewtopic.php?f=11&t=2319&p=25632#p25632

gotta watch for some of these Chinese parts, they can be very temperamental, yet other times solid... from my experience anyway.

rigmo wrote:

TGillies wrote: ↑Mon May 11, 2020 1:40 am I wasted 3 of those MRF chips on the same board, tried both MRF9180 & MRF186. had the exact same problem as you at first, it would only give me reduced power before blowing altogether. i came to the conclusion it was the board itself.

viewtopic.php?f=11&t=2319&p=25632#p25632

gotta watch for some of these Chinese parts, they can be very temperamental, yet other times solid... from my experience anyway.

Board is good for sure 100%... she can support 500w but values of capacitance is not right values for right matching.. i get efficiency over 70.5%
I will make measurements again.. with MRF810... i also burn two mosfet before i se where is problem ...

TGillies wrote:.

Electronically wrote: ↑Mon May 11, 2020 10:56 pm Change R1 r2 r3 for better results also

rigmo wrote:

Electronically wrote: ↑Mon May 11, 2020 10:56 pm Change R1 r2 r3 for better results also

Hi Sir can you tell more info.. ? exact value?

rigmo wrote:thank you ... i will try and, record
c4 c5? 1n 10n or?

Electronically wrote: ↑Wed May 13, 2020 6:49 pm I have to say why does the Chinese boards not have any protection at the output chips ie mrf186 & 9180.would it not be sensible to put a zener diode onto the bias supply to protect the (expensive) transistor from too much bias voltage? .just a thought.

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Bton-FM wrote:

Electronically wrote: ↑Wed May 13, 2020 6:49 pm I have to say why does the Chinese boards not have any protection at the output chips ie mrf186 & 9180.would it not be sensible to put a zener diode onto the bias supply to protect the (expensive) transistor from too much bias voltage? .just a thought.

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Probably because they wanted to cut as many corners as possible to increase price margin.

Electronically wrote: ↑Wed May 13, 2020 7:44 pm

Bton-FM wrote:

Electronically wrote: ↑Wed May 13, 2020 6:49 pm I have to say why does the Chinese boards not have any protection at the output chips ie mrf186 & 9180.would it not be sensible to put a zener diode onto the bias supply to protect the (expensive) transistor from too much bias voltage? .just a thought.

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Probably because they wanted to cut as many corners as possible to increase price margin.

Possibly so we keep blowing the chips as there market grows each time we keep buying.

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