Hamradio 360 Antenna Analyzer

The place to talk about specific amateur radio equipment and all types of accessories, fixes, repairs and modification.
Post Reply
User avatar
Prostetnic
Regular
Regular
Posts: 8
Joined: 14 Aug 2016, 08:29
Location: Towcester

Hamradio 360 Antenna Analyzer

Post by Prostetnic »

I have just built one of these and wonder if anyone here as done the same.
It seems to work very well and is easy to use, especially with it connected to a PC.
I would be interested to know how accurate it is and perhaps how to check that without another analyser.
oh5nxo
Regular
Regular
Posts: 40
Joined: 24 Apr 2017, 18:41
Call Sign: oh5nxo
Location: kp30xr

Re: Hamradio 360 Antenna Analyzer

Post by oh5nxo »

I don't have one, but a crude test might start as follows:

Leave the jack open. SWR infinity everywhere? Probably around 10 or 20 instead, limit of the instrument. Short it with the shortest possible piece of wire. SWR also infinity? Find a 100 ohm resistor and stick it in. SWR ought to be 2 everywhere, veering off a bit at the 30 MHz end, more so if the resistor is not the non-inductive sort. Add another in series, 200 ohm in total, SWR now near 4 ? Replace one of the resistors with a 1nF cap, SWR now around 2.6 at 3 MHz, going down to near 2 at 30 MHz.

No guarantee on those numbers,
Juha
User avatar
Prostetnic
Regular
Regular
Posts: 8
Joined: 14 Aug 2016, 08:29
Location: Towcester

Re: Hamradio 360 Antenna Analyzer

Post by Prostetnic »

Thanks for the information Juha. I will give it a go and see what I get.
User avatar
Prostetnic
Regular
Regular
Posts: 8
Joined: 14 Aug 2016, 08:29
Location: Towcester

Re: Hamradio 360 Antenna Analyzer

Post by Prostetnic »

I have checked it out as you suggested and with various wire antennas.
It does perform well around the 50 ohm mark but response is not so good away from that.
So works fine for trimming an antenna but would not recommend it if you wanted to do a full frequency sweep.
Post Reply