I have just bought from Venus trading…SW-3b, a 3 band 5w radio.
Like many other similar radios this has a little LED which light which is supposed to light up/illuminate on transmitting and on the small screen there is a graduated ‘bar’ graph(?) indication of power output. This is shown in the link, but i’m sure most of these small radios are similiar.
I’ve field tested the radio twice, using a linked dipole from SOTA Beams which uses 6m of RG174 feeder and an 11.5v battery. . No led lights up and there is NO bar graph indication on the screen that shows it is transmitting other than, “TX” being displayed.
I’ve also tested it from my home QTH using a similar length of coax to a simple dipole via a tuner which I use with my home radio a 10w Ten-Tec radio… No LED lights up and again there’s no power indication on the screen I’m transmitting other than “TX”.
However, If I use a dummy load the LED lights up and there is a horizontal bar the full width of the screen. I asked the company about this and they suggested I measure the power output which I did using an 11.5v battery. This showed an output of 5v. and the LED worked and there was a horizontal bar showing I was putting out 5 watts on the radio.
My technical ability exhausted at this point I took it to a an amateur whose technical skills I’d rate very highly. Using his extensive test equipment the radio was shown to put out 5 watts, including altering the SWR readings by varying and even connecting it to a 2m aerial giving an SWR of 4:1. In all the tests the radio worked as it should, the LED illuminated and the bar graph on the radio showed 5 watts going out.
a) He suggested I may have incorrectly used or checked my linked dipole. So I did another test this morning using my home aerial with the same type of coax to a simple dipole. I was able to exchange RST with the first ham I answered. No LED lit up - no bar graph etc., etc.,
b) He did comment that a 6m length of RG 174 coax may be so ‘lossy’ that there was not enough power going out of the radio to illuminate the LED and./or the bar graph.
c) I have used myYou-Kits HB-1b many times using the same linked dipole and through my home QTH aerial and I always get a display output showing ;a power output of up to 5watts.
d) I have been picked up by the RBN network over most of Europe in the couple of times I’ve used this radio.
Has anyone else used RG174 with a SW 3b ??
Has anyone experienced similar issues with this radio?
Is it the fault of my ‘lossy’ SOTA beams linked dipole & home aerial ??(I have no other aerials to use/test)
Should I simply insist on returning the radio as it is faulty?