DSE D-3800 P/S
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DSE D-3800 P/S
My D-3800 died last night... though, mostly my fault...
It suffered a short circuit on the output of the P/S.
Voltage is no longer regulated, sitting at 21V so I suspect one of the regs. I had some spares but they've been misplaced since the last fix I did to it.
Casualties:
1 x Yaesu FT-8900R (no crowbar circuit protection on this P/S). Little diode gone inside the radio so hopefully will be an easy fix... I hope... D1042 a P6KA18 transient voltage suppressor. Someone mention it's just a fancy name for a 15-16V zener.
1 x D3800 P/S
Near Misses:
FT991 - funny enough it powered down, I got the output off the radio quickly... massive panic set in... reconnected it to a battery and it powered up like nothing had happened. Phew!
Moral of the story - install protection on the P/S output... aannnnndd don't leave croc clips plugged in!!!!
It suffered a short circuit on the output of the P/S.
Voltage is no longer regulated, sitting at 21V so I suspect one of the regs. I had some spares but they've been misplaced since the last fix I did to it.
Casualties:
1 x Yaesu FT-8900R (no crowbar circuit protection on this P/S). Little diode gone inside the radio so hopefully will be an easy fix... I hope... D1042 a P6KA18 transient voltage suppressor. Someone mention it's just a fancy name for a 15-16V zener.
1 x D3800 P/S
Near Misses:
FT991 - funny enough it powered down, I got the output off the radio quickly... massive panic set in... reconnected it to a battery and it powered up like nothing had happened. Phew!
Moral of the story - install protection on the P/S output... aannnnndd don't leave croc clips plugged in!!!!
Re: DSE D-3800 P/S
After you fix your supply you need to put something like this circuit between the power supply and the rig .
I only use the over voltage part of this circuit on my D-3800 supply.
Cheers
Ken
I only use the over voltage part of this circuit on my D-3800 supply.
Cheers
Ken
- Attachments
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- Reverse Polarity and Over Voltage Circuit.docx
- Over voltage Protection
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Re: DSE D-3800 P/S
Thanks Ken,
Yes a right pain.
Hayden
Yes a right pain.
Hayden
Re: DSE D-3800 P/S
Thanks for that Ken.
I'll be assembling one as soon as the weather allows me back into the 'man cave'.
Cheers
I'll be assembling one as soon as the weather allows me back into the 'man cave'.
Cheers
______________________________________________________________
Colin
VK2CSW
Where are we going? And exactly why am I in a hand-basket?
Colin
VK2CSW
Where are we going? And exactly why am I in a hand-basket?
Re: DSE D-3800 P/S
When you fix your supply I would suggest that you place a resistor (SOT) across TR7 so that the fan runs very slow all the time.
This stops the annoying fan from coming on at full speed when you only have a receiver running.
Cheers
Ken
This stops the annoying fan from coming on at full speed when you only have a receiver running.
Cheers
Ken
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- D3800 power supply diagram.pdf
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Re: DSE D-3800 P/S
The amount of DX I've probably missed because of that fan....
I'm going to get a few 2N3055's today.. see which one has blown.
Regards
Hayden
I'm going to get a few 2N3055's today.. see which one has blown.
Regards
Hayden
Re: DSE D-3800 P/S
I made a video on repairing one of these power supplies.
https://www.youtube.com/watch?v=plA_8Erz3R4&t=861s
Brendan VK3MH
https://www.youtube.com/watch?v=plA_8Erz3R4&t=861s
Brendan VK3MH
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Re: DSE D-3800 P/S
put a 17 volt idiot diode across output
even old cbs have the $1.50 avalanche device acts as a crowbar
even old cbs have the $1.50 avalanche device acts as a crowbar
Tread your own path
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Re: DSE D-3800 P/S
Maybe they are built better than we thought - although I'm pretty sure the 8900 took one for the collective Yaesu teamVK2LK wrote:Close shave on the FT-991!! That was some serious good luck!