CHASE GPR4403 Laboratory Receiver Service manual PLEASE (2023 Update)

A plea for HELP. We have a CHASE GPR4403 laboratory test receiver displaying UNCAL on the LCD. The operators manual describes this message as relating to a RF or IF fault. Trawling the web I find that CHASE have been taken over several times since our receiver was manufactured and emails to the new owners draw a blank. Surely there must be more than one (our) GPR4403 out there and someone MUST have service data. Is it you...or do you know a man who can help. PLEASE help me repair our Radio Club's test receiver if you possible can. Thanks in anticipation Dave Amateur Radio club of Nottingham.

Reply to
Dave Bullock
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Op donderdag 25 maart 2010 09:54:35 UTC+1 schreef Dave Bullock:

Dear Dave,

I have exactly the same problem with my Chase receiver, did you manage to fix this problem? Hope to hear from you. Many thanks Jim

Reply to
harry.beukenoot2

Hi guys, Did you ever get your Chase radio working again? Simon

Reply to
simondavidbond

The problem with this units is they loose their Flash Erom memory, causing them to go into Un Calibrated state (Uncal), this is normally due the Main Batteries going Faulty or in a Non Rechargable state, being switcedh off an d un charged for a long period of time, or the unit being taken apart by so meone not realizing if the internal back up battery gets discounted or is f orced flat it will cause eRom loss.

Chase went under years back, there were one or two companies that claimed t hey could fix or re Flash the Roms, but were either unsuccesfull or very ex pensive.

Reply to
chris.binder

Looks like these threads are years old so this will probably never be read! I designed the receiver. There is no service manual, unless one was done after I left the company. The receiver was calibrated automatically by computer over the rs 232 port before the units were shipped. The calibration points were stored in eprom. Depending on the year of manufacture there was a backup battery or 1 farad cap as backup. As the original spec was 10 years receiver life most receivers have now probably died. The cal software ran on a BBC micro. Any programming info is long gone.

Reply to
Tony

Talk about planned obsolescence!

So the receiver calibration might change over time and there is absolutely no way to fix this as there is no calibration program left anywhere. I/m assuming if anything was changed in the receiver that it would then need calibration...

And people wonder why I like fixing electronic toys prior to the 2000s! Stuff after 2000 is not nearly as fixable - too many one-off or customer parts.

Then there is the question of who owns the device they bought. As an example one brand of pinball games shuts the game down if it is operated on 50 or 60 Hertz and that is different than the line frequency (60/50Hz) that the game was originally set up for.

John :-#(#

Reply to
John Robertson

This makes me wonder if this end state of calibration data vanishing after xx years was a design requirement (specified by who?) or a byproduct of the design approach taken (to increase machine flexibility? reduce parts count? etc.).

Reply to
Three Jeeps

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