Grape 1 Troubleshooting
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Jeff Brennan
May 20, 2024, 11:05:49 PMMay 20
to hamsci-grape
The good news is that I finished building the Grape 1. The bad news is that, other than a nice spark, the unit is not functioning. Are there any troubleshooting guides or anyone who can assist? Thanks - Jeff, AC7IJ
Joe Hobart
May 21, 2024, 12:16:49 AMMay 21
to hamsci-grape
Brad,
I have build 5, repaired 2 more, and I have some repair parts.
What have you checked so far? What test equipment do you have?
Two quick checks:
With GRAPE + power + antenna + GPSDO the light should light and you should hear something (weakly) with a pair of earphones connected to the output.
R7 is a chip resistor in the lower right hand corner of the board. One side should measure 5 volts to ground; the other side should measure about 2.5 volts to ground.
What antenna do you use?
Remember that propagation has been highly variable recently. WWV 10 MHz daytime and 5 MHz nighttime seem best here.
If you cannot get it going, send it here, and I will repair. I am good in QRZ.com
73,
Joe, W7LUX
Flagstaff, AZ
I have build 5, repaired 2 more, and I have some repair parts.
What have you checked so far? What test equipment do you have?
Two quick checks:
With GRAPE + power + antenna + GPSDO the light should light and you should hear something (weakly) with a pair of earphones connected to the output.
R7 is a chip resistor in the lower right hand corner of the board. One side should measure 5 volts to ground; the other side should measure about 2.5 volts to ground.
What antenna do you use?
Remember that propagation has been highly variable recently. WWV 10 MHz daytime and 5 MHz nighttime seem best here.
If you cannot get it going, send it here, and I will repair. I am good in QRZ.com
73,
Joe, W7LUX
Flagstaff, AZ
Jeff Brennan
May 21, 2024, 10:01:12 PMMay 21
to hamsci-grape
Brad - quick update. Power output at R7 was correct. I did some more troubleshooting and was able to determine that the LED light (pwr) was itself not working. I put another regular-size LED in place and it worked just fine. I’ll order another one and continue testing the unit. Hopefully, this will be the only issue. 73, Jeff, AC7IJ
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