Wonder Wand mobile HF Antenna for Yaesu FT-817

I have always been fascinated by the idea of making long distance contacts using small hand-held radios. Anyone can work DX if they can put up big antennas and have a powerful transmitter. But to make contacts over hundreds or thousands of miles using a station you can set up in a corner of a desk or even hold in your hand, and which requires no external antenna - now that's a real challenge!

QRP operators know that a few watts into a length of wire can easily work the world, especially on CW. But the wire needs to be long, and requires supports to keep it up in the air. For ultimate portability you want an antenna that can support itself and be carried with the radio, or even mounted on it, so it is ready in an instant and can be used anywhere.

It was for this reason that I purchased a Miracle Whip several years ago. At the time it seemed like the perfect antenna to use with my newly-acquired FT-817, one that would allow me to fully exploit its portability. Of course, a small antenna like that is not going to be very efficient, but it did allow contacts to be made in situations where it would otherwise have been too much bother to carry or set up the radio.

The FT-817 and Miracle Whip were sold in 2002, but a few years later I bought an FT-817ND and an ATX Walkabout antenna. The ATX is an excellent antenna that works extremely well for its size. However I was still on the lookout for something better.

The Wonder Wand had been marketed for some time as a British version of the Miracle Whip. In 2007 I purchased the new Wonder Wand Combo with a tunable counterpoise. I was not all that impressed with it, and wrote a rather unfavourable review after carrying out a comparative test with the ATX using WSPR beacon mode to obtain signal strength reports. After an exchange of emails with the manufacturer who felt that my findings were untypical, it was discovered my example had an unsoldered joint that may have contributed to the poor performance. The manufacturer offered to replace it with a sample of a brand new model that has not even been advertised at the time of writing. So here is my exclusive world first review of the Wonder Wand L-Whip Antenna.

Description

The Wonder Wand L-Whip looks similar to a Miracle Whip, and almost identical to the earlier Wonder Wand Combo. It mounts directly on the back of the radio using its integral PL-259 connector, and has two controls that face forward for ease of access. The lower control is a bandswitch which has eight positions, marked 1.8-3.5, 7, 10, 14, 18-21, 24-28, 50 and UHF. These positions select taps on an inductor, according to the amateur band you want to use.

Above this is a rotary control that is continuously calibrated from 1 to 10. This is a tuning capacitor that is used to tune the antenna for maximum signal and minimum SWR on the selected band. The tuning is quite sharp and this control allows the antenna to cover a wide range. Although the L-Whip is clearly designed for the ham bands, it could be used to receive the short wave broadcast bands as well, although I have not checked to see if the entire short wave spectrum is tunable without gaps in the coverage.

On top of the antenna is mounted a 7-section black telescopic whip 125cm (50 inches) in length. As with the Miracle Whip and earlier Wonder Wand models, the whip antenna is not removable. That's a pity, as it would reduce the length of the antenna when packed away.

At the bottom of the antenna there is a knurled thumbscrew for attaching a ground or counterpoise. One of the claimed benefits of the Miracle Whip and earlier Wonder Wand models was that the transformer loading allowed them to be matched to the transmitter without the need for a ground. The L-Whip can be tuned to a reasonable match without a ground or counterpoise on some bands, but I would only recommend this for casual listening as it incurs a substantial loss of transmitting efficiency.

Although a ground or counterpoise is required for best results it is not particularly critical. If the transceiver is being powered from a mains supply then there may be a good enough ground connection through the negative lead back to the house wiring earth connection. Alternatively a wire can be used to ground the antenna to the copper pipes of a central heating system.

When used out of doors, a few metres of wire laying on the ground is generally all that is needed. It should not be necessary to use separate quarter wave lengths for each band. However, the length should not be close to a half wavelength - which would have a high impedance and be ineffective - so you might need to use a shorter wire on the higher frequencies. I found that performance can be affected by the choice of counterpoise, so some experimentation may be necessary.

As it was winter time when this evaluation was carried out, all testing was performed indoors with the FT-817 and L-Whip standing on a corner of the desk in my first floor shack. Grounding was provided through the negative lead of the shack power supply, but I also made up a short fly lead with an alligator clip on one end which I used to link the antenna's ground terminal to a nearby central heating radiator.

Electrical principles

The Miracle Whip adopted the novel and rather controversial approach of using a specially made variable transformer to match the short whip to the 50 ohm transceiver. This enabled a low SWR to be achieved - at the expense of efficiency due to losses in the transformer. The transformer was a fragile component that was easily burned out by the application of more power than that for which it was designed - bear in mind that the Miracle Whip was originally designed specifically for the 5W FT-817.

The original Wonder Wand followed the same principles but used a more robust toroidal transformer with fixed taps pre-tuned to each amateur band. This reputedly allowed it to handle up to 40W PEP, and to survive the accidental application of 100W - which would destroy a Miracle Whip in a heartbeat. However the fixed taps precluded tuning to allow reception of other parts of the short wave spectrum, or even to compensate for the effects of different situations, except by adjusting the whip length.

Although the Wonder Wand L-Whip also has a toroidal inductor to save space, it uses more conventional methods to match the antenna. The small box contains a miniature L-match tuning circuit - hence the antenna's name. The antenna's designer, Carl Peake, a medium-wave broadcast engineer, claims: "the fact that ALL our MF sites use an "L" Match to drive their single mast monopoles is testament that this type of tuner always gives results!"

The toroidal inductor is tapped to provide the correct amount of inductance needed to match a short whip on each of the HF amateur bands. This is a compromise compared to using a continuously tunable rollercoaster as in many home-brew L-matches, but is obviously the only practical solution for reasons of cost and size.

The tuning capacitor is a polyvaricon type as used in transistor radios. Probably because of the low breakdown voltage of the tuning capacitor, the Wonder Wand L-Whip is rated to handle no more than 15W PEP, which is less than the Miracle Whip. FT-817 owners should not be concerned about this, but users of other low power radios will need to watch their output power.

On the air

Getting on the air with the Wonder Wand L-Whip is simplicity itself. Just attach it to the antenna socket on the back of the radio, turn the band selector to the band you are listening on, and peak the tuning control for maximum noise or signal.

If you are powering your radio from batteries, or your mains supply does not provide a good ground, then as already mentioned you'll need to attach a counterpoise wire or a ground wire to the ground screw on the antenna. The rule of thumb with all vertical antennas is: the better the ground, the better the signal. If the noise level increases when you put your hand on the radio, you need a better ground.

The tuning of this antenna is pretty sharp, which is a good sign. If the tuning seems really broad, or you can't find a clear point of maximum signal at all, then something is wrong. I found that four times out of five, I could tune the antenna to no SWR bars on the FT-817 meter just by ear. On the fifth occasion a slight tweak of the control during the first few seconds of the transmission was all that was necessary to get a perfect match.

It's very satisfying having a continuously variable tuning control to select the absolute optimum tuning position, rather than the click stop tuning of the earlier Wonder Wand models, which always made me feel that it wasn't tuned up properly.

Antenna analyzer measurements showed that the SWR on each band was often quite a long way from 1:1. This is probably the result of the fixed inductor tuning. However it is nothing to worry about. It close enough to keep the FT-817 happy, with zero SWR bars being obtainable on every band except 160m, on which it was still possible to obtain a very reasonable two bars.

The Wonder Wand L-Whip provides good reception on all the amateur bands, with plenty of signals reaching S9 or more even without the aid of the FT-817's preamp. Now you can use your '817 as a bedside radio! It's also quite easy to make contacts, at least on 20m and up, as long as you are realistic about what QRP into a short antenna can achieve.

For my first try on the air I called Henry, ES7FQ, who was almost end-stop calling CQ on 20m SSB. After asking me to repeat my call a couple of times, he came back with a 5 and 9 report (blaming splatter from an adjacent frequency for why he had trouble copying me) and said "Your 5 watts is coming over here very well." This was very pleasing! However, on the whole, making contacts on SSB with QRP and such a small antenna is going to be difficult, and you need to get used to the fact that a lot of stations you call just won't hear you.

It's much easier to make contacts on the narrow band modes such as PSK31 and CW. I have made several solid contacts on 20m at distances of around 1,000km running 5W using PSK31, PSK63 and MFSK16. The FT-817 plus L-Whip and a small "netbook" style of computer makes a perfect portable data modes station.

On the lower frequency bands I have not, so far, made any contacts of any significant distance although it is possible to make local contacts of a few km on 80m and 160m. The bands above 20m have been more or less dead during the test period, so I haven't been able to try them, but I would expect results to be better than on 20m. I once made a 10m FM contact into Malta (9H1) from a mountaintop using a modified CB handie with a rubber duck antenna and a couple of watts, so when conditions are good anything is possible.

WSPR tests

The FT-817 / L-Whip combo was operated for many hours using WSPR (Weak Signal Propagation Reporter) mode. Its signals were spotted on 20m, 30m, 40m and 80m all over Europe, while signals were received from as far afield as Tasmania. You can't get much further from the UK than that!

These WSPR tests gave me the opportunity to compare the signal radiated by the Wonder Wand L-Whip with that radiated by my main antennas located in the attic a couple of metres above my shack. At a rough estimate the signal radiated by the L-Whip is about 13dB down on a dipole on 30m and 20m. That's the same difference as turning the power down from 100W to 5W. This represents a drop of just over two S-points, though to be fair, most transceiver S-meters are more like 3dB per S-point, which would result in a more than 4 S-point drop. On 80m the signal reports received using the L-Whip were 15dB below my dipole, which being shortened using end-loading is probably a few dB below a full-sized dipole by itself.

Using WSPR I did some comparative tests with the ATX Walkabout antenna. The L-Whip's designer claims that in his own tests the two antennas are just about equal. In my WSPR tests the ATX seemed to get reports that were slightly better than the L-Whip. As noted earlier, the particular ground / counterpoise used can affect the performance of these short whip antennas, so this may explain the difference.

VHF and UHF

I live in a VHF black hole and never hear anything above 30MHz except during sporadic-E openings in May and June on 6 meters. However, the Wonder Wand L-Whip has two switch positions marked "50" and "UHF" so I thought I would do what I could to test them.

The telescopic whip is too short to be a quarter wave on 6 meters. While turning the tuning control anticlockwise with the switch in the "50" position the SWR can be reduced to no bars on the FT-817 meter. However the received noise level and presumably transmitted signal goes down in this direction. Turning the control clockwise the noise increases, though no peak is reached, but the SWR increases considerably. Checks with an antenna analyzer show that an SWR minimum occurs several MHz above 50MHz, probably corresponding to the frequency for which the whip is a quarter wave long. Therefore it does not appear to be possible to use this antenna on 6 meters.

On 2 meters you use the final "UHF" position, turn the tuning control fully clockwise and shorten the whip to a length of 48 centimeters (19 inches) to make a quarter wave. It is not possible to use this antenna as a 5/8 wave, unlike the ATX Walkabout, which provided a few dB of gain in this configuration.

The whip sections are too long to make a quarter wave for 70cm, and no other position was found that did not result in "High SWR" warnings from the FT-817. Therefore, despite the "UHF" marking, it does not appear to be possible to use the L-Whip on 70cm.

Conclusions

The designer of the Wonder Wand L-Whip set out to create a Miracle Whip killer, and in my opinion he has succeeded. This tiny antenna covers all amateur HF bands from 160m to 10m, is usable for both receive and transmit, and it can be used as a quarter wave on 2m into the bargain. It looks good, is nice and easy to use, and is based on tried and tested antenna design principles.

Although I did not have the opportunity to directly compare the L-Whip with a Miracle Whip, having sold the latter several years ago, the fact that the L-Whip uses a conventional L-match design rather than the lossy variable matching transformer makes me strongly suspect that the L-Whip will be a better performer than its Canadian rival.

Compared to the ATX Walkabout the L-Whip is lighter, better looking, easier to set up and much quicker to tune. Unlike the ATX there is no need to fiddle with counterpoise lengths and shortening or extending whip sections to get a match. However, the ATX does repay this extra effort with, in my experience, slightly better performance, and it is cheaper.

I haven't mentioned the price yet, mainly because I don't know it as at the time of writing the Wonder Wand L-Whip has not been officially announced. However, the designer has stated it will be "about the same as the Miracle Whip." It will be available from Martin Lynch and Sons, to whom all enquiries about price and availability should be addressed. (It would be nice if you could mention me while doing so, then I might be able to get a few favours from Chris. :) )

Verdict

So is the Wonder Wand L-Whip the Holy Grail that enthusiasts of ultra-portable HF operation have been searching for? I think so. Yes, it would be nice to have a bit more efficiency, but I think the L-Whip is close to the practical limits of what can be achieved with an antenna this small and this light.

The Wonder Wand L-Whip is a great little antenna. It now has a permanent place in the shoulder bag that carries my FT-817 and its other accessories.