Review: Micro-Portable QRP Antennas
Daimon Tilley G4USI tests the Moonraker Whizz Whip, Whizz Loop and SPX-100 for holiday use. Read about how he fared.
Although licensed for many years, my lengthy period of radio-inactivity meant that I had never operated from abroad. My return to the hobby just over a year ago has re-ignited my love for radio so I decided to correct that during this year’s summer holiday. I knew I couldn’t devote too much time to radio abroad because primarily it’s a family holiday and I have two young children to entertain, as well as an XYL to keep sweet, so whatever form my operating abroad was to take, it needed to fit the available time.
A Holiday with a Difference
This year we decided to holiday with a difference and use an InterRail ticket to travel between nine cities, in six countries over about three weeks. The itinerary was primarily one or two nights in each location, with a week in the Italian Lakes and looked like this:
1. Two nights in Paris
2. Overnight train from Paris to Milan
3. One week in a villa on the shore of Lake
Lugano in Italy, right on the Swiss Border
4. One night in Lucerne, Switzerland
5. Three nights in Germany, with one each
in Freiburg, Heidelburg and Cologne
6. Two nights in Amsterdam
7. One night in Brussels
8. Return home to Somerset
I wasn’t sure how I would fare with QRP operation from hotels in the big cities but hoped to do reasonably well at the Villa with a longwire. Additionally, as so much time was to be spent on the train (over 1,700 miles in total), it seemed like a lot of fun to think about operating some HF train-mobile CW! I began to think this through. How was I going to operate on HF with an antenna on a train in a practical, and allowable, way? Clearly, I was not going to be able to use a conventional wire antenna so I picked up my copy of PW for inspiration and began to browse the adverts. I came across the Moonraker pages and noticed the Whizz Whip and Whizz Loop antennas. They looked the ideal size but could they do the job? A further look at the Moonraker website showed an SPX-100, a telescopic base-loaded verti-cal of diminutive size. All three antennas were small and compact − ideal for rail travel.
Now, I know that we are at a point of low sunspots and poor propagation and, in the world of antennas, larger is usually better. Additionally, for QRP work, every bit of radiated power counts but if I wanted to work from a train, surely it would be worth a try? Moonraker very kindly offered to loan the three antennas for a review and I received them the same week. In this article, I will examine each one in turn, report on my testing before the holidays, as well as the ultimate tests – city hotels and train mobile.
Moonraker Whizz Whip
The Whizz Whip, Figs. 1, retails at £99.95 and is certainly compact. The whip element attaches to the tuning box via a BNC connector and measures a little under 21cm closed and approximately 130cm when extended. The tuning box is small at 8x4x2cm plus protrusions. On initial inspection, it was the one I thought that most fitted my needs to be compact and reasonably unobtrusive, looking like a conventional FM radio receiver antenna. The antenna is designed particularly with the Yaesu FT-817/818 in mind. When plugged into the SO239 socket on the rear, the unit is nicely supported on the same surface as the rig. Intrigued, I opened the box to peek inside and found a really well engineered mechanical switch connected in an interesting way to windings on a toroid, Fig.2. I wasn’t able to investigate further for other components or attributes because the whole unit was quite a tight fit and I didn’t want to risk causing any damage. The unit came with an A4 instruction sheet advising that the device covered 3.5MHz to 460MHz on transmit and 0.6- 500MHz on receive, and could cope with 10W of RF on AM, CW and SSB. There were some brief bullet points on how to tune the antenna, which on HF involved using the tuning knob and tuning for peak noise and, on VHF/UHF, setting the dial to a preset point and adjusting the whip to a quarter wavelength. The instructions say a counterpoise is not required but a quarter-wave counterpoise can be used to improve performance. For my use, being strictly HF, a quarter-wave counterpoise would be longer than the radiator so I dismissed it as impractical.
Moonraker Whizz Loop
I had been sent the V2 version of the Whizz Loop, Figs. 3 and 4, which covers 40-10m and retails at £79.95. This consists of two parts, a control box of similar size to the Whizz Whip, also with a single tuning control, and approximately 1.5m of thick copper wire, with each end terminated in a ring terminal. The idea is that you uncoil this wire into a rough loop shape and connect each terminal to the screw terminal posts on the tuning box. Again, power is rated at 10W. Tuning instructions are vague but I found tuning for maximum noise on receive was a good starting point. In a similar design to the Whizz Whip, it is obviously designed to sit nicely on the back of the FT-817/818.
Fig. 1: Moonraker Whizz Whip
Fig. 2: Moonraker Whizz Whip internal view
Fig. 3: Moonraker Whizz Loop V2
Fig. 4: Moonraker Whizz Loop V2 internal view
Inside is a conventional LC network, with a fixed toroid and adjustable polyvaricon capacitor. I wasn’t able to see the reverse of the PCB to determine the nature of the network (series, parallel, etc.). Only the variable capacitor was tuned by the control. My initial reaction to this antenna was that it was somewhat more obtrusive than the whip and might cause more interest. I was mostly concerned about how train guards might react in the current security
climate, if they saw a bunch of electronics they recognised as ‘odd’ and didn’t understand. As the antenna is a loop, there was no suggestion of using a counterpoise.
Fig. 5: Moonraker SPX-100 Fig. 6: Testing the SPX-100 on WSPR using the uBtix Go-Box
The Final product is a little more conventional looking base-loaded vertical and is advertised as covering 80-6m. The SPX-100, Fig. 5, is in several parts. First there is a telescopic whip, not dissimilar to the Whizz Whip but terminated in a screw thread. This screws into the top of a base loading coil. The coil has a number of holes, or taps, which are selected by means of a ‘wander-lead’ arrangement according to your band. Finally, there are both PL259 and BNC connectors that screw onto the base of the loading-coil to suit your rig, as well as a right-angled PL259 adapter. I know that a number of amateurs use the BNC connector on top of their FT-817/818 for ‘pedestrian-mobile’ activities. Priced at £49.99, this antenna is the cheapest of the three and I expected it to be the most efficient given the loading coil rather than a tuning arrangement. It is advertised as a nine band ‘plug-n-go’ antenna. The antenna arrived in a plastic bag and without instructions but these were easily found on the Moonraker website, which indicated that 5W power handling is guaranteed, with a (presumably non-guaranteed?) 25W maximum input power. It is still pretty compact and will pack down to just 30cm − ideal for travelling. Tuning is achieved by a combination of plugging the ‘wander-lead’ into different tap points, as well as adjusting the whip length. The instructions give a starting position and length for each band, when used with a quarter-wave counterpoise. Again, for me at HF, a full-size counterpoise at anything below about 21Mhz was going to be a non−starter on a train. When setting up this antenna, the build quality did feel a little on the cheap side. The ‘wander lead’ felt fragile and the BNC adapter just came apart in my hands, although it didn’t stop it functioning and the black plastic sleeve merely slipped back on over the connector.
Testing before Travel
We were travelling light due to nature of our journey so while it would have been nice to take all three antennas along, I really could only afford space for one, plus a random wire for those occasions where I could erect one. I determined, therefore, to test them out at home and choose the one I thought best for my holiday travels. I decided that I would test in three different ways. First, I would test SWR with an antenna analyser. I would then carry out real-world tests on 40m and 20m − the two bands I was most likely to use − using both WSPR (Weak Signal Propagation Reporter software) and the Reverse Beacon Network.
As these antennas are touted as portable and have tuning facilities, I opted not to use any additional tuning or matching networks. If they were to do their job, they needed to ‘stand on their own two feet’ and it seemed self-defeating to introduce more potential losses. Of course, I fully appreciate that a dummy load can provide a perfect SWR, so this test was not going to give me an indication of efficiency but neither did I want to use an antenna that was going to be so mis-matched that my finals were at risk. I had recently borrowed a friend’s MFJ Antenna Analyser for another purpose and decided to use it to see how these antennas would tune. I found the SPX-100 the most difficult to tune, needing a combination of choosing the right wander-lead position and length of whip. The instructions didn’t seem to help, probably because I wasn’t using a counterpoise, and even when I tried using a short counterpoise I couldn’t get an acceptable match below 40m while even 40m was problematic. I could get an SWR of 2.1:1 at 7.180MHz but the CW portion of the band was not usable, with the best SWR available ranging between 4:1 and 5:1. I could, however achieve a usable (less than 2:1) SWR on higher bands but for the reasons identified found it too fiddly for practical use. The Whizz Loop provided usable (less than 2:1) SWRs on 40m and above. The Whizz Whip was not usable (in my view) on 40m with an SWR of 2.5:1 without counterpoise but this came down to just below 2:1 with the short counterpoise. On 30m and above it was usable with and without counterpoise. Both the Whizz Whip and Whizz Loop could give a reasonable state of tune by ear alone, with the loop having the best ‘null’ but, to be honest, I achieved a much better SWR using either the antenna analyser or the rig’s SWR meter.
In order to strike the right balance between getting some acceptable SWR results and not having a full quarter-wave counterpoise, I relented and did use a (short) counterpoise on the two verticals, of about 10ft of hook-up wire. In order to run the WSPR tests I used the antenna analyser to achieve the best possible SWR on the 40, 30 and 20m bands and then connected the antenna to my uBitx Go- Box on the patio at home, Fig. 6. I did this during the course of one afternoon and each antenna had three WSPR transmissions. Power varied between about 7W and 10W according to the band, but each antenna received the same power on the same band. The results were as I have shown in Table 1. As can be seen, the two verticals managed the most spots and best distance covered. I was encouraged that the antennas could propagate but WSPR is designed with weak signals in mind. Could this performance be transferred to CW?
Reverse Beacon Network
The WSPR tests gave some encouragement but if I was going to use these antennas, it was going to be on CW, as I wasn’t going to be taking digital mode functionality on holiday. Over the next week, on two separate days, I carried out a number of reverse beacon tests. I used both a Yaesu FT-818, which I have for review, and my own Xiegu X5105, which I recently purchased. Both rigs were running 5W from the patio again. I made three long CQs for each of the three antennas on both 40 and 20m bands. Nothing, diddly-squat, nada! The second day of testing returned the same result. I was obviously disappointed but, to be honest, I wasn’t that surprised either. In peak propagation conditions, I have no doubt I could make QSOs on these antennas, but we are in far from peak conditions currently. At this moment in time, with QRP, a good (full size) antenna is almost essential.
Going on Holiday
Despite the poor results, I still intended to try CW from a train because I was going to be spending over 1,700 miles on one. I decided to take my Xiegu rig, which has an internal auto-ATU and internal battery pack, for maximum versatility. I also packed a random wire antenna, counterpoise, power supply, keyer and other items into a small camera bag rucksack. There was room for just one of the three Moonraker antennas but which
to take? Logic would have dictated taking one of the verticals, based on the WSPR results, but both were a little too big for operating on a train table, clearly needed a degree of counterpoise for best SWR, and I found both verticals tricky to tune. I decided to take the loop because I found that easier to tune by ear, with sharper nulls and matching well without a counterpoise. Perhaps propagation might improve while I was away. It was worth a try for the tiny size of the antenna.
Well, it wasn’t fantastic! Taking the gear was always going to be ancillary to the holiday. I couldn’t clear off to a park or hilltop for hours on end so I snatched an hour or so when I could. In Paris, I tried both the Whizz Loop and the random wire on the roof terrace of the hotel, but noise levels were S9 and I couldn’t hear anything, let alone work it. On arrival at the Villa on the shores of Lake Lugano, I erected the 58ft random wire in a tree but just about 15ft high. The location was idyllic but there was a large mountain just three quarters of a mile due North. That said, I did manage half a dozen QSOs. These included a couple of CW skeds with friend and club member Peter G0EYR, where we successfully completed short QSOs on the 40 and 30m bands over two days. Another friend, Eugene G4AIU, could clearly be heard on 40m but sadly could not copy me due to the noise at his QTH. I also managed some CW QSOs into Germany and SSB contacts into the Dodecanese and Scotland. Then the travelling really kicked in. I arranged a couple of skeds on train journeys with Eugene. However, the Whizz Loop could hear nothing but S9 noise on pretty much any band. As well as propagation conditions, the fact that all the trains I travelled on relied on many kilovolts of electricity flowing a few feet above my head probably didn’t help! In the photo, Fig. 7, you can see me set up on the train from Heidelberg to Cologne. I posted this photo on some QRP social media pages and received quite a reaction. These included from people who successfully operate on steam trains in the UK to others who told me to beware the Doppler effect! One or two contributors pointed out that in the photo I had the loop orientated in the wrong direction, with maximum radiation being transmitted up and down the train, rather than out the windows. I tried an orientation of 90° to that shown on the next train trip, with no effect. Finally, a contributor stated he felt that train windows had a thermal film that might hamper radiation too. It was on that particular train that the guard asked me what I was up to. Fortunately, he was very friendly and enjoyed my explanation of amateur radio. It was his first ever experience of seeing someone trying to operate from one of his trains. Whatever the factors, it was impossible to operate. I could just about hear some FT8 above the noise on the train and would like to have tried a WSPR transmission but I wasn’t equipped for it. I tried working from other cities too. From my Frieberg hotel operating position, Fig. 8, I tried both the loop and the random wire dangling out of the hotel’s fourth-floor window. I also tried both methods in Cologne and Amsterdam but all to no avail − just too much man-made noise to hear anything. It would be interesting if readers could share their own QRP experiences in city locations with poor propagation. Perhaps you could drop a line to the Letters page?
Fig. 7: The author on the train in Germany.
Fig 8: The Whizz Loop in a hotel in Freiburg, Germany.
And Home Again.
I was pleased to have made some contacts but not satisfied with my city-centreoperating. I was also concerned not to have had a QSO or even a single reverse beacon spot on any of the loan antennas. So, I decided to give them all one last try. I set up on the patio again and transmitted 10 CQs on 20m from each antenna and had no replies and no spots on the Reverse Beacon Network either. Frustrating!
I am fortunate to live rurally with a really low level of man-made noise. Now I realise just how lucky I am! Operating from citycentre hotels was impossible on this trip and I didn’t have the time to visit parks or hilltops nearby. It was a great shame I couldn’t make a CW QSO from a train. That surely would have been a lifelong memory but there were just too many compromises. Low power, electrically noisy trains and tiny antennas all conspired against me. The West Somerset Steam Railway is not far from here though...... perhaps I need to try that. As for the antennas, the Whizz Whip and Loop were well made for their job, the SPX-100 felt a little more fragile, but in current conditions none of these antennae could help me make a CW QSO. The WSPR results may indicate some possibility of success on FT8 or similar digital modes but I didn’t try that. Roll-on the next sunspot maxima! Finally, I would like to record my thanks to Moonraker for the very kind and prompt loan of the various antennas. Full details, with prices and availability, are on their website: www.moonraker.eu
Table 1: Results of WSPR Tests
This article was featured in the November 2019 issue of Practical Wireless