开云体育

I have a U3S which has started to act strangely. When I feed my beam it behaves well transmitting every 10 minutes as programmed. I also have an end-fed long-wire that is resonant on the Ham frequencies. The U3S used to feed that antenna with no problem. However, now when connected to the long-wire it will go through a single transmit sequence (WSPR) just fine. I get reasonable reports. However, when the second transmit sequence starts the U3S displays the opening "splash" screen and then just starts reading the GPS. HOWEVER, it thinks that the splash screen is still on because in you press the right (Edit) button it asks "do you want to reboot". Cycling the power gets it back to normal.

This behavior is consistent. Works on all bands the beam will tune. On any band with the long-wire (including bands that the beam will tune)? it transmits once and gives good reports. It will not transmit again, until it is rebooted. I tried inserting a QRP antenna tuner between the long-wire and the U3S hoping that a bit of isolation would help. No change in behavior. Transmits only once then locks up.

Please note that I've been using this for months on both antennas with excellent results. This trouble started only after I added two additional BS170 PAs. However, I am still operating with only 5 volts.?

Any ideas.? Sorry to trouble you all, but I really want to work the higher bands that are not accessible to the beam.

Thanks and 73. Dick W7DAX

I would suggest that you reset the idle current on the PA's as that point has changed because of the 0 point has changed. Because of the 2 added PA's? Also it sounds like you are getting RF back into the U3S so you would? possibly? need to add a Unun some distance from the U3S. I would start there...I run my U3S in this configuration. Ferrite beads etc may help you out too. Bill KN8DMK

I have the same problem. How is it measured? Where to connect the ammeter?
--
Piotr SQ4MIK