Small, lightweight, capable, manual QRP tuner - Does it exist???
Small, lightweight, capable, manual QRP tuner - Does it exist???
Resonate QRP antennas are good in the field. I have a SotaBeam Band Hopper II and love it. EFHW antennas I like as well. But I have always liked the idea of being able to tune up virtually any length of wire on any band. This, unless someone knows something I don't, can basically only be achieved with a tuner.
So, I have acquired some tuners, apart from the built in ones on the Xeigu radios I own. Here is my collection up until a week ago.
Now while each of these tuners are very capable, they all have their own strengths and weaknesses. For field use I have found that I prefer manual tuners. It just gives me a sense of simplicity and less to go wrong. My absolute favourite tuner, for the field and a lot of the time in the shack, is the ZM-2. My only dislike of it is the need to deal with two fly leads and the fact that it can be bumped off its tuned position, especially when sitting in a precarious spot on a summit fighting with the wind or even when cramped in a small Bothy Bag trying to keep the elements off yourself and your equipment. So my search for the ultimate tuner has continued.
Then after seeing some videos on the Wonder Wand, where the ham had discarded the small whip antenna and hooked it directly to a wire antenna, it got me thinking. The Wonder Wand is a bit of a strange beast. It has been around for sometime. There is a small following of hams who love them, a small number who have bought them and tell the world not to waste your money and generally considered by the greater majority of ham’s as being a seriously compromised antenna that one might use when there is absolutely no other alternative available…..but be prepared to be disappointed.
All of that said, some of these videos I have watched depicted hams using them as a tuner for a long length of antenna wire and getting quite reasonable results. So it got me thinking, how would it perform with a long wire if used for summit activations. It is small, it can be attached directly to the radio and the wire antenna attaches directly to the tuner. Would it work though? Looking at the price of a Wonder Wand immediately put me off as it was just too much for me to fork out in the hope that it might work.
And then I came across this copy on Aliexpress.
It is an obvious Wonder Wand copy but it had some good reviews which indicated to me that the tuner, at least must work to some degree. The price to my door was only NZD $65, or USD $38, so I took the gamble. It was delivered in just under two weeks.
Since receiving it nearly a week ago I was keen to get out and attach it to wire and see how good it matches it to a radio. This hasn’t been able to happen due to some work commitments, howling winds and today, heavy rain. Not to be deterred though, and much to the chagrin of my long suffering wife, I strung a 42 foot length of wire across the dining room, down the hallway and terminated it to a picture hook in an end bedroom. I hooked up the NanoVNA and was stunned that I could get a match of less than 1.5 to 2 SWR on 160, 80, 60, 40, 30, 17, 15, and 12 metres. On 20 metres it was 1:1 over the whole band. 10 metres it was 1.5 to 2.1, 6 metres I could only get between 2.5 to 3 and then just for giggles I tried 2 metres and 70 cm and managed 1.5 to 2.1 And all of this without a counterpoise.
My testing method here today can not in anyway be considered scientific or definitive but I have to say it is most definitely worthy of further testing once the weather clears, which I will do and report back here.
What other ‘Manual’ tuners are other hams using in the field for QRP?
And then a few days later.
Well, field testing began today, albeit I only had a 40 minute window of opportunity. First thing I had to do was get away from my QTH as it is situated in a small valley and is not kind to portable setups. So, I drove to a nearby village about 25 km away and set up on a small reserve from which I have had good success with previous portable antennas.
The antenna I used today was just two 42' lengths of wire, one as a radiating arm in a reverse 'V' over a 6 meter SOTA pole and the other length running directly underneath as a counterpoise. I was specifically try to replicate SOTABeam's recommended way of setting up their Band Spring Midi, as this is the antenna that I have on order and hope to use with this tuner.
This is a picture of SOTABeam's recommended way of securing the two wires at the ATU end.
This is how I had had it set up.....
This actually had the wires approximately 4 " of the ground whereas SOTABeams seem to have them right on the ground. Will this have any effect? Not sure; further testing required.
So anyway, I started to go through the bands and try and get a match. I only managed to try 40, 20 and 10 meters.
I set the mode to AM and 'ear-balled' each band, then I started a SWR chart and made adjustments to the variable capacitor as required. I was able to get under 1.2 SWR on 40 and 20 meters but only 1.4 on 10 meters. The bands appeared to be in reasonable shape as the digital signals could be heard strongly, but just not a lot of phone activity. Not surprising for mid afternoon on a sunny weekday.
Anyway, on 40 meters ZL3RIK came booming through as he was doing a portable activations of a lake in the north island. I know Rick and his portable setup and it would have been an FT-891 on 100 watts, normally through a sloper or dipole raised on a 6 meter pole.
We QSO’d. I gave him a report of 59, he gave me a report of 53. I wasn’t too surprised considering I was only using 5 watts. Below is a picture of our signal path.
I was quite happy with that, 714 km. Anyway, time was running out for me. I tuned in on 10 meters and could hear activity in the States but nothing local. I heard a ham in Nevada calling CQ and getting little response, so I thought even though only running 5 watts I would throw my hat into the ring. I called and he heard my signal but couldn’t get my callsign out of the noise level. After 4 attempts he wished me 73’s and carried on.
So for my first field test using the Chinese equivalent of the Wonder Wand Tuner, 5 watts on the IC-705 and 2 random wires setup in a prescribed manner for the SOTABeam’s Band Springer, I was happy. A lot more testing required and some further refinement but overall I am satisfied enough with the initial results to continue further testing. I shall keep the thread updated.
Cheers
Phil ZL3CC
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