When I turn on my unit the display shows 800 not the last station I had
tuned into, does this have an internal batterie that can be changed.
Thanks
Robert
No, it’s not frozen, I can tune in a frequency ok, it’s just if I set say 358 freq then turn it off, turn back on again the display the shows 800 not the last tuned freq (358) it’s no big deal, just though tidier had a back up batterie it would have been nice to change it.
Page 1-1 of the IM
I can’t find any reference to a “battery” in either the IM or the MM (I ran the MM through OCR so I could search it).
So it looks like the EAROM (a 1970s name for “EEPROM”) may be faulty. They do have a limited number of write cycles.
Thanks Peter, sounds like the culprit, I will try and find one if that’s possible.
You need to talk to Simon the Avionic bench technician at Stapleford, he will know in an instant what is wrong with it.
You will find him in the back of the SFC maintenance hangar, sorry I don’t know the phone number !
Perhaps a capacitor in the switched mode power supply negative line…
/Sam
Perhaps a capacitor in the switched mode power supply negative line…
Can you post more detail?
A capacitor cannot pass DC current so putting one “in” the negative line would block the power supply output.
The KR87 has a buildt in power supply that generates a few voltages that is required for proper operation.
KR87 is a very reliable unit. The items that tend to go bad are the display, light bulbs and the power supply by means of a poor diode or rectifying capacitor. If I dont remember all wrong the negative voltage is used for “memory function” and perhaps something more less noticeable by the user. I also pay extra attention to the unit at 225° since the indicator seems to draw little more current and any power supply faults may become visible as a “jumping needle”.
/Sam
