Did you check that there is an insulting strip loin top of the PTO mechanism? There is a very close fit between the bottom of the DR7 solder ?and the grounded metal below the DR7 just below the display elements. This often results in dead segments.
Drake, ?in later radios, glued a grey piece of high voltage cardboard on top the PTO assembly. Your radio looks like a pretty early one so may not have this.
Also, the notion suggested by another, a bad foil, makes sense because the same segments are dead on both the MHz displays.
Gary
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On Mar 21, 2021, at 7:19 AM, Steve Wedge, W1ES/4 via <
w1es@...> wrote:
The second digit is missing two segments. It looks like a display or driver issue to me (assuming the etches and soldering are okay).?
I can¡¯t remember if the display drivers are open collector or not. Check the output of the display driver for each digit.?
73,
Steve Wedge, W1ES/4
Time flies like an arrow.? Fruit flies like a banana.
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On Sun, Mar 21, 2021 at 06:34, Mike Davidsohn G3ZCC <mike@...> wrote:Hi Everyone, hope you are safe and well.
I have fitted the rebuilt DR7 and the up/down and jumper works just fine.
The first two digits seen to be missing the same part of the display which is a lovely blue colour.
I have also knocked the PTO calibration so I will have to fix that.
The fact that the first two digits are missing the same segments leads me to believe that it is not the display itself.
I have attached a picture of the TR7 on 28.888
Any thoughts
Kind Regards
Mike
G3ZCC
