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I ordered a final board from a store in Germany for the 818 and installed it. I made several contacts to Chicago and Connecticut and around the Southeast on 40 meters. It was a good day for my hamfest special FT 817. Maybe I can pick up a cw filter someday. Just glad to get it on the air. I made the mistake of telling Yaesu USA that I wanted one for my 817. I probably should have said it was an 818. Maybe they would have sold me one then instead of telling me no parts were available. 73s John N4HNO
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That’s great news. Now for my 2 week ago question that has yet to be answered. Was it difficult? Were instrument adjustments necessary? Are you a repair guru and an smd type guy? Thanks Mike Davis WA1MAD
On Oct 7, 2024, at 4:41 PM, Tech Guy <tech48055@...> wrote:
I ordered a final board from a store in Germany for the 818 and installed it. I made several contacts to Chicago and Connecticut and around the Southeast on 40 meters. It was a good day for my hamfest special FT 817. Maybe I can pick up a cw filter someday. Just glad to get it on the air. I made the mistake of telling Yaesu USA that I wanted one for my 817. I probably should have said it was an 818. Maybe they would have sold me one then instead of telling me no parts were available. 73s John N4HNO
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It was easy. Desolder two small coax cables, power jumper, ground jumper and other ground. Tack solder a wire to the pad the positive jumper connected to and put a milliamp meter in line. Set the radio to 1.8 Mhz CW. I used a dummy load. Press ptt and adjust the pot on the right to about 42 ma when ptt pressed. Move to the left pot and adjust to about 82ma. Remove the wire and put the positive jumper back. I did add sone heatsink compound to the board before I screwed it to the heatsink. Look at the videos mentioned for details. I used to do tv repair years ago. This is much easier than pulling the smt fets that I couldn’t find anyway. Just be careful with heat and touching other pads or parts.
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That's great, thanks for sharing your success with us. I suspect you're right about saying it was for an FT-817.
Glad she's up and running, enjoy!
On Oct 7, 2024, at 18:59, Tech Guy <tech48055@...> wrote:
It was easy. Desolder two small coax cables, power jumper, ground jumper and other ground. Tack solder a wire to the pad the positive jumper connected to and put a milliamp meter in line. Set the radio to 1.8 Mhz CW. I used a dummy load. Press ptt and adjust the pot on the right to about 42 ma when ptt pressed. Move to the left pot and adjust to about 82ma. Remove the wire and put the positive jumper back. I did add sone heatsink compound to the board before I screwed it to the heatsink. Look at the videos mentioned for details. I used to do tv repair years ago. This is much easier than pulling the smt fets that I couldn’t find anyway. Just be careful with heat and touching other pads or parts.
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I have replaced my 2004 FT817 PA twice. Ordered the board from Yaesu and installed it.
I am EE and have done a lot of electronics although in work relied on techs to handly most of that. Seems many dont like giving tools to EEs, but I have done most at home.
Replacing the PA is some what simple. Do need to unsolder the old board and install including soldering the input and output coaxes to the board. Then there is an alignment where you connect an Amp meter in the power line and adjust 2 pots, one for each PA transistor. You will need a multi meter. There are good instructions on some of the FT817/8 boards.
Dont be afraid of doing this. Not like small surface mounted ICs. Everything is rather large and easy to solder.
73, ron, n9ee/r Ron Wright, N9EE/R Hernando Co ARES EC
Spring Hill, Florida also n9ee55@...
On Monday, October 7, 2024 at 08:08:14 PM EDT, Ken N2VIP <ken@...> wrote:
That's great, thanks for sharing your success with us. I suspect you're right about saying it was for an FT-817.
Glad she's up and running, enjoy!
On Oct 7, 2024, at 18:59, Tech Guy <tech48055@...> wrote:
It was easy. Desolder two small coax cables, power jumper, ground jumper and other ground. Tack solder a wire to the pad the positive jumper connected to and put a milliamp meter in line. Set the radio to 1.8 Mhz CW. I used a dummy load. Press ptt and adjust the pot on the right to about 42 ma when ptt pressed. Move to the left pot and adjust to about 82ma. Remove the wire and put the positive jumper back. I did add sone heatsink compound to the board before I screwed it to the heatsink. Look at the videos mentioned for details. I used to do tv repair years ago. This is much easier than pulling the smt fets that I couldn’t find anyway. Just be careful with heat and touching other pads or parts.
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Thanks Ron. I wonder why the PAs fail. Hi SWR? Shorted coax? I read about the FETs going into self oscillation if internal battery is left in place. I also think I read that ND and 818 are better protected. Mine is new to me, non ND, almost brand new from an estate/SK? I'm using the LDG Z817 to minimize risk. Now to decide if I should get a PA board as a spare before they are gone. 73
Mike WA1MAD
On Oct 8, 2024 2:05 PM, "Ron Wright via groups.io" <lt_wright_flg@...> wrote: I have replaced my 2004 FT817 PA twice. Ordered the board from Yaesu and installed it.
I am EE and have done a lot of electronics although in work relied on techs to handly most of that. Seems many dont like giving tools to EEs, but I have done most at home.
Replacing the PA is some what simple. Do need to unsolder the old board and install including soldering the input and output coaxes to the board. Then there is an alignment where you connect an Amp meter in the power line and adjust 2 pots, one for each PA transistor. You will need a multi meter. There are good instructions on some of the FT817/8 boards.
Dont be afraid of doing this. Not like small surface mounted ICs. Everything is rather large and easy to solder.
73, ron, n9ee/r Ron Wright, N9EE/R Hernando Co ARES EC
Spring Hill, Florida also n9ee55@...
On Monday, October 7, 2024 at 08:08:14 PM EDT, Ken N2VIP <ken@...> wrote:
That's great, thanks for sharing your success with us. I suspect you're right about saying it was for an FT-817.
Glad she's up and running, enjoy! Ken, N2VIP On Oct 7, 2024, at 18:59, Tech Guy <tech48055@...> wrote:
It was easy. Desolder two small coax cables, power jumper, ground jumper and other ground. Tack solder a wire to the pad the positive jumper connected to and put a milliamp meter in line. Set the radio to 1.8 Mhz CW. I used a dummy load. Press ptt and adjust the pot on the right to about 42 ma when ptt pressed. Move to the left pot and adjust to about 82ma. Remove the wire and put the positive jumper back. I did add sone heatsink compound to the board before I screwed it to the heatsink. Look at the videos mentioned for details. I used to do tv repair years ago. This is much easier than pulling the smt fets that I couldn’t find anyway. Just be careful with heat and touching other pads or parts.
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I don't think the issue is that the boards are "prone to fail" instead I think it's a matter the use case of taking the radio in the field, rigging up temporary/compromise antennas, then Mr. Murphy shows up...
A PA board failure renders a radio useless, and with the FT -817 it's replacement is fairly easily made for a reasonable cost.
Also, with the phenomenal # of FT-8-7/717nd/818 radios in the field, the number of failures may be high compared to other radios, but proportionately the same as other radios.
On Oct 8, 2024, at 13:33, Michael Davis via groups.io <maddmd818@...> wrote:
Thanks Ron. I wonder why the PAs fail. Hi SWR? Shorted coax? I read about the FETs going into self oscillation if internal battery is left in place. I also think I read that ND and 818 are better protected. Mine is new to me, non ND, almost brand new from an estate/SK? I'm using the LDG Z817 to minimize risk. Now to decide if I should get a PA board as a spare before they are gone. 73
Mike WA1MAD
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Thanks Ken. Good insight.
Mike WA1MAD
On Oct 8, 2024 3:41 PM, Ken N2VIP <ken@...> wrote: I don't think the issue is that the boards are "prone to fail" instead I think it's a matter the use case of taking the radio in the field, rigging up temporary/compromise antennas, then Mr. Murphy shows up...
A PA board failure renders a radio useless, and with the FT -817 it's replacement is fairly easily made for a reasonable cost.
Also, with the phenomenal # of FT-8-7/717nd/818 radios in the field, the number of failures may be high compared to other radios, but proportionately the same as other radios. Ken, N2VIP On Oct 8, 2024, at 13:33, Michael Davis via groups.io <maddmd818@...> wrote:
Thanks Ron. I wonder why the PAs fail. Hi SWR? Shorted coax? I read about the FETs going into self oscillation if internal battery is left in place. I also think I read that ND and 818 are better protected. Mine is new to me, non ND, almost brand new from an estate/SK? I'm using the LDG Z817 to minimize risk. Now to decide if I should get a PA board as a spare before they are gone. 73
Mike WA1MAD On Oct 8, 2024 2:05 PM, "Ron Wright via groups.io" <lt_wright_flg@...> wrote: I have replaced my 2004 FT817 PA twice. Ordered the board from Yaesu and installed it.
I am EE and have done a lot of electronics although in work relied on techs to handly most of that. Seems many dont like giving tools to EEs, but I have done most at home.
Replacing the PA is some what simple. Do need to unsolder the old board and install including soldering the input and output coaxes to the board. Then there is an alignment where you connect an Amp meter in the power line and adjust 2 pots, one for each PA transistor. You will need a multi meter. There are good instructions on some of the FT817/8 boards.
Dont be afraid of doing this. Not like small surface mounted ICs. Everything is rather large and easy to solder.
73, ron, n9ee/r Ron Wright, N9EE/R Hernando Co ARES EC
Spring Hill, Florida also n9ee55@...
On Monday, October 7, 2024 at 08:08:14 PM EDT, Ken N2VIP <ken@...> wrote:
That's great, thanks for sharing your success with us. I suspect you're right about saying it was for an FT-817.
Glad she's up and running, enjoy! Ken, N2VIP On Oct 7, 2024, at 18:59, Tech Guy <tech48055@...> wrote:
It was easy. Desolder two small coax cables, power jumper, ground jumper and other ground. Tack solder a wire to the pad the positive jumper connected to and put a milliamp meter in line. Set the radio to 1.8 Mhz CW. I used a dummy load. Press ptt and adjust the pot on the right to about 42 ma when ptt pressed. Move to the left pot and adjust to about 82ma. Remove the wire and put the positive jumper back. I did add sone heatsink compound to the board before I screwed it to the heatsink. Look at the videos mentioned for details. I used to do tv repair years ago. This is much easier than pulling the smt fets that I couldn’t find anyway. Just be careful with heat and touching other pads or parts.
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I just found this article. http://fura.se/images/stories/teknik/ft817_final_amp_mod.pdf
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Can you please share German shop details?
73 de LY5EZ
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hi Ken
after replacing every board in my old FT-817 by brand new ft-818 boards (see in this group)
I could set current to the FINAL UNIT as mentioned.
BUT no power out at all. Carrier is ok... Receiving is ok on front / rear socket...
Should use the scope to see whats going on. Frustrating....
cheers - Ray, DL1EGR
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John, are you adjusting bias for driver and finals, or just the finals? If it's just the finals, you'd normally set the second pot for twice the current, or 84mA. I realize it's a small difference, but balance is important.
Dave
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I only adjust the finals. Will check driver bias also.
As metioned before: it is FT817 frame with complete new FT818 interioer.
There might be a lot to adjust also...
cheers Ray
Am 21.11.2024 um 02:46 schrieb Dave Mueller AA3EE via groups.io:
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Показати цитований текст
John, are you adjusting bias for driver and finals, or just the
finals? If it's just the finals, you'd normally set the second pot for
twice the current, or 84mA. I realize it's a small difference, but
balance is important.
Dave
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Michael Davis
Raimund Reh