My SGC-237 antenna tuner broke. I followed the troubleshooting guide and I'm not sure if it's the cheap parts or the CPU. None of the LEDs light.
The CPU is a 68HC11E9FN2 52 pin PLCC chip.Q1 is a surface mount 2N2222, mounted on the bottom of the board. I don't know the value/part number of D1. (It's a 1N914)
Measuring the collector of Q1 shows a 'low' of about 2.0 volts when power is applied. This seems high.So I think it's the transistor. The 'FWD' voltages goes down as the power increases. That doesn't seem right, either.
Ordered the CPU, transisitors and diodes. I'll post an update after I troubleshoot.(It wasn't the CPU.)
Propagation Links and Stuff
- http://www.taborsoft.com/ SkyCap Wizard is very cool.Uses VOACAP engine.
- VOACAP - also rocks. Old but goodie. Free.
- http://www.g4hfq.co.uk/plphelp/plphelp.htm - Polar Plot for measuring antenna patterns
- http://www.orbitfr.com/Mailers/AppNote1002/AppNote1002v5.html - Using gating to remove multipath in antenna pattern measurements
- http://www.ngdc.noaa.gov/seg/geomag/faqgeom.shtml - Compass and geomagnetism info
- http://home.ict.nl/~arivoors/ - NEC Antenna modeling program. Integrates with VOACAP. Free
I try to read these links.
Adventure Wilderness Society - Combine the great outdoors with QRP ham radio
QRPAPCI - International QRP radio society. QRPARCI # 12060
QRP-L - A new QRP mailing list
FISTS - CW enthusists, FISTS # 13317