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FT 817 problem for portable operators


#1

After many years of use and abuse my FT 817 experienced a problem—it would work on the internal battery but not from an external source connected to the power connector.
After some time spent looking at the schematic and the radio, I discovered a break in a pcb track, close to the power connector. It would seem that when used regularly for /P operation, where the external power connector is repeatedly inserted/ pulled out creates mechanical stress on the pcb causing a track to go open circuit.
The fix is a simple, though delicate, matter of making a solder bridge across the pcb track.
Having made the fix, I mentioned it on air to Rob–G4RQJ who says he and others have experienced the same problem. Portable operators of FT 817’s take note.

Best wishes Gordon G0EWN


#2

Gordon,

Twice, I have experienced the (almost) ‘opposite’ problem of the 817 working on the external supply, but with the internal battery no good because it wasn’t recharging. I’ve had this fixed once before, and I recall it was also due to PCB damage from rear connector stress.

The problem has appeared again, but I’ve not (yet) bothered getting it fixed this time. I always use a SLAB anyway!

Tom M1EYP


#3

In reply to G0EWN:

Well worth knowing Gordon. Can I suggest a slight improvement. Rather than bridging the crack with solder, remove a little more of the soldermask from the tracks and bridge the crack with a small stub of wire. A solder bridge alone is quite likely to fatigue fracture quite quickly whereas a wire bridge will be more resilient.

As for plugging into the socket repeatedly, I’m surprised how well some of these consumer grade connectors stand up to repeated use. When I was working on super secret hush-hush sonar stuff, the plugs and sockets where rated for 25 insertions only. After that the PCB would be scrapped and the connector on the back plane changed. As we sold these boards to Her Majesty’s Boy in Boats at £25k a shot (and you need a lot of board for a sonar system) there was shouting all round if anyone unplugged anything.

The point to this waffle being, don’t exercise difficult to change connectors to the end of their life. I leave my 817 power cable always connected and have another connector on the end of the cable. Should that and its counterpart on the batteries wear out then they are easy to replace unlike the one on the 817.

Andy
MM0FMF


#4

In reply to MM0FMF:

I agree, Andy, I had the same problem and bridged with a piece of wire.

Somehow I doubt that leaving the power connector in the rig will solve anything, every time the rig is put in the rucsac or taken out that connector will be pushed or bumped and that movement is also likely to get transferred to the board, but it is still probably a worthwhile precaution.

I miss my old 817, a rig with real personality, I will probably replace it eventually!

73

Brian G8ADD


#5

In reply to G8ADD:

My 817’s live permanently wedged into waterproof plastic “kliplok” cereal storage boxes, complete with LiPo’s, mic, headphones and patch lead for ATU (when used). Gives excellent mechanical and rain protection. Fortunately the mic seems to be very forgiving of soakings on a regular basis :wink:

73 de Paul G4MD


#6

In reply to MM0FMF:
Hi Andy, Tom and Brian,

many thanks for the ideas and information. I will implement your suggestions re the use of wire rather than solder bridge and also the use of a ‘sacrificial’ connector.

I used the solder blob as I was in somewhat of a hurry to get the radio operational again to carry on a sequence of activations.

My FT 817 is now around 6 years old and gets a lot use for driving microwave transverters, HF QRP as well as SOTA–both as home station and out portable. I have wide-banded the TX/ RX so as to use 60m and added voltage on TX for transverter switching.

I was a little sceptical of these radio’s when they first appeared, after all many compromises have to be made in such a radio. However I have come to truly appreciate its versitility and compactness. In short it is one of the best radio’s I have owned.

Thanks again guys, 73s Gordon G0EWN


#7

In reply to G0EWN:
This could be the problem I have with my 817, Sometimes the connector requires a wiggle for the radio to power up despite being snugly in the socket. A problem that started about a year ago. Thanks for bringing this up, Further investigation will be carried out. Sean M0GIA


#8

In reply to M0GIA:

John GW4BVE made me aware of the potential problem with the power connector shortly after I got my rig. I have the power lead permanently connected and the cable is strapped back to the rear of the rig where there is a convenient threaded socket, presumably for earthing the rig. I have had no trouble over the past 3 years with this arrangement.

73, Gerald


#9

In reply to G4OIG:

My cable is held in place by the softcover so there’s no movement. But I like your idea of using the earth screw to secure the cable. I shall try and fix mine like that this evening.

Andy
MM0FMF


#10

Gordon G0EWN:

The problem can probably be prevented. When I bought my FT817ND 2 or 3 years ago, the fault was well known amongst SOTA ops so I decided to guard against it from the start. In keeping with my 706, I wanted a permanent flying lead anyway. The external ‘mod’ was as follows:

  1. Spiral bind the power lead and plug and mate them angling the plug ‘southwest’ as viewed looking at the rear panel.
  2. Fasten a blank crimp ring terminal to the earthing point and tighten it up so that it’s parallel with the connector and in contact with it. (I used a yellow x 4BA.)
  3. Tyrap the connector to the crimp terminal and include the power lead. Loop it back to do the latter.

The 817 now has a flying power lead and the connector is strain relieved. A wire can first be added to the crimp terminal if required for use as a static earth.

I made a ‘too large’ over-cover for the rig using corrix board. This is a sliding fit fore & aft but overlaps the rig front and rear further protecting mechanically sensitive areas. It can be slid back and forth to expose the front panel during the activation or cover front & rear for transport and is held in place by a thin bungie.

My 817 has not done a huge amount of work but I have not had a problem of this nature yet because the connector has only ever been mated once. Touch wood!

73, John G4YSS.