Viking VK40 Field Test Report | Metal Detecting Books

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Towards the end of 2004 I was fortunate enough to be given the opportunity to test the newest detector in the Viking range, the VK40. The VK40 is the latest of the computerised models with LCD screen, and the addition this time of membrane key pads on the control panel and a 9.5in polo search coil. The VK40 currently rounds off the VK range, which includes the successful VK20 and VK30 models that also feature LCD screens and incorporate a new control box design.

First Impressions

On opening the box containing the VK40, I was immediately drawn to the actual size of the detector. It is quite a long machine and only breaks down into two parts as the 9.5in polo search coil is hardwired into the control box. As a result the detector would probably be more suited to a larger holdall for transporting about as opposed to a conventional rucksack or smaller bag. Once out of the box the detector is straightforward to assemble. Just push the lower stem into the upper one (the detector is made up in a two piece “S” configuration), and then turn the lower stem so that it wraps the coil cable around the stems. Remember, however, to leave some slack and not tighten the cable too hard. Once this is done, you can then adjust to the desired length via the spring lock clip on the lower stem and the positioned holes on the upper stem. When the correct height is achieved tighten both stems together via the locking collar at the end of the upper stem. Having assembled the detector, all that remains to do is to install the single PP3 battery into the battery pod drawer located just under the speaker on the control box. The new type of control box is a new design from the previous VK20 and VK30 models. It is a complete unit as opposed to being in two parts, and has a futuristic look to it. It is made of plastic and the control panel is in two tones of green above, and below the LCD screen, with three of the keypads in red while the rest of the control box is of a black colour. Just above the control box is the rubber handle and above that the combined arm cup and detector stand. The arm cup incorporates a Velcro strap to help keep your arm in place. Unlike many computerised metal detectors the VK40 is very simple to operate and doesn’t come with a large handbook; the manual from front page to back page is just 12 pages long and very easy to follow. The VK40 model features a threaded wheel nut balance device at the end of the lower stem where the search coil is attached. This is to ensure that the detectors 9.5in polo coil stays rigid and in place, and the wheel nut can be adjusted to angle the search coil to any desired position.

Keypad Functions & LCD Screen

The VK40 offers three different detection search modes: Motion Mode, All-Metal Mode, and Non-Motion Mode. It also offers two types of ground modes one being Inland, and the other being Beach. Other functions include the ability to adjust settings for Discrimination and Sensitivity. If desired there is also a function whereby you can override the automatic Auto Power-Off switch. This, like many modern day cameras, has the ability to turn the detector off if neglected from use after approximately five minutes. All the functions and modes are easily activated using the membrane keypads as described below. Working from left to right, the first key pad is marked as a circle with half a line going through it. This is the Power On/Off Key. Pressing this once will turn the detector on, and pressing it again will turn it off. Next you have a Downward Arrow; this key will switch from the current detection setting to the Motion Mode. When the detector is in the Menu mode, the downward arrow key can be used to decrease the Sensitivity or Discrimination setting. The middle keypad is a “P”, which can be used in either the Motion or All- Metal modes to accurately pinpoint a target by keeping the finger pressed on it while you pass the search coil over a likely target. And when the detector is in the Non-Motion detection mode keeping the finger pressed on this keypad will retune the audio threshold to its preset level. Next to the “P” key pad is one marked as an upwards arrow. By pressing this key while in the Motion mode it will switch to the All-Metal mode or vice versa depending on the mode you are in. When the detector is in the Menu mode (just like the downward arrow function) the upwards arrow can be used to increase the setting in Discrimination or Sensitivity. Finally, there is the keypad marked Menu. This key switches the detector into the Menu mode, allowing the Sensitivity, Discrimination and Ground settings to be adjusted. Motion Mode is a silent search mode and there will only be an audible signal given when the search coil passes over a metallic object and the search coil is in motion. However, it is useful to remember that, depending on your discrimination setting, if a signal sounds off one way only or it breaks up then it could be rubbish. On the other hand, if you get a clear signal either way when you swing the coil and a high number is noted on the LCD screen - with a large amount of blocks showing - then the target would be worth digging. All Metal Mode is a facility that provides a continuous faint audio threshold tone. This helps to find the smallest of signals possible to be picked up. In this mode the audio output will be continuous, but slowly retunes to the threshold level preventing the detector from drifting out of tune; but again it requires the search coil to be moving in a similar fashion to that of the Motion mode. In this mode discrimination is automatically seen via the LCD Screen (in the same way as the Motion mode setting). The All-Metal mode does not work when you switch the ground setting from Inland to Beach. Non-Motion Mode is similar to the All-Metal mode for it also provides a faint audio threshold tone through both speaker and headphones. However, in this mode the detector does not automatically retune. It enables the search coil to be held stationary over a target to allow accurate pinpointing. Depending on ground conditions and temperature, the threshold tone may experience a change in its level; if this does happen it can be retuned by pressing the “P” keypad for a few seconds. Discrimination on the VK40, as with the VK20 and VK30 models, is determined by looking at the readings on the LCD Screen via numbers and blocks that appear on the target ID bar. For instance, if you were to receive a signal and saw on the screen a low number such as 10 or 15 - appearing with only one or two blocks - then it would suggest you have found rubbish such as a small piece of iron or a small rusty nail. But if you received a much higher number - say from 65 to 70 and five or six blocks appearing - it would suggest a piece of metal of higher conductivity has been found and that it would be worth digging up. The discrimination numbers range from 0, which will pick up all metals, right through to 90 that will pick up only larger objects of higher conductivity. When using the detector for the first time it is a good idea to keep the discrimination set to 0 so that you can get acquainted with numbers and blocks; after this you will probably have found a desired setting that you are happy with. Sensitivity can be set to the optimal level for the site you are searching. For example if you are working a site that is not contaminated with bad mineralisation such as coke, and does not have electric fences or pylons nearby, you will probably get away with a higher setting such as 90. Alternatively, if you do have problems with false signals or conflicting numbers appearing on the screen you may have to reduce the sensitivity level. With in-the-field practice you will soon gain experience of both the discrimination and sensitivity settings.

Field Appraisal

I took the VK40 to a number of stubble fields and found that it performed really well over most of the sites I visited. I set the discrimination to 30 and, depending on the length of the stubble, the sensitivity on 60 to 80 (leaving it in the All-Metal mode). Initially, I began to wonder if the detector was working properly for nearly every signal I was getting came up on the ID bar as 10-15. But in the end this just proved the accuracy of the discrimination. The fields I search have a lot of iron and non-ferrous rubbish in them and, just to be doubly sure, I dug a number of these signals to see what they were. As expected, they turned out to be small fragments of iron or nails. Eventually, finds started to pick up and the better readings on the LCD screen started to come through: first a musket ball, then a small bronze weight, and then a button. All came in at 65 to 70, with six to seven blocks appearing. I was not only impressed at the accurate readings, but also with the actual depths. The small weight came up from around the 5in mark and the musket ball was equally as deep. I then found a large buckle fragment, a Victorian farthing, and a Scottish medallion showing thistles and a date of 1832. This came up from a depth of around 8in. Then came up a very nice and unusual brass weight giving a reading of 90 on the ID Bar. It is a 4oz weight with markings that still can be seen, and also came up from a very good depth. On another site we visited the VK40 did very well for the conditions and managed to find nine coins. Some had been lost by potato pickers of immediate post war years, but amongst them were two worn George III halfpennies and a very thin token with 3d on it; depths achieved were again excellent. While searching over another field the VK40 picked a large amount of nonferrous junk fragments. These were mainly old furniture fittings and the like, but I have included a photograph of one particular piece that seems to differ from the rest. I wonder if any readers know what it once could have been a part of? Its seems ornately made, is copper alloy and if I was to take a guess, I would say it might have been one half of a combination pipe tamper/nutcracker.

My original trials, just before Christmas, were carried out on a fairly run-of-the-mill stubble field that I had searched many times over the years. The VK 40 did manage to find a number of objects that we had missed on previous occasions. I was impressed, but wondered whether this was simply to do with the farmer ploughing slightly deeper than normal. This was because when I had been searching the site on previous occasions we had recovered - along with some more unusual finds - a lot of material that was apparently associated with the dumping of “town dung”. However, from recent aerial photography and archaeological sources, the farmer had informed us that some of our finds were more likely to be associated with a building that had stood directly in front of his house and in the very field that we were now searching. The farmer believes that this may have been a Roman granary store; but, having conducted some research myself, I have come to the conclusion that it was probably a “souterrain” or earth house. Earth houses are fairly common in my part of the country, but are normally considered to be of the Bronze Age or earlier periods. However, some excavations of them have recovered Roman artefacts such as fragments of pottery or glass. But, in itself, this doesn’t point to them having been used by the Roman Army. On the other hand this doesn’t rule them out as having been used by Roman soldiers as temporary shelters or marching camps (of which there are a number of traces of such in my area). The trouble with this field is that there are two natural humps in the terrain, forming a feature of saddle shape, and this would have given some shelter from the winds - perhaps even for an early settlement. Throughout the years I have been searching this site I have never found anything in the form of Roman artefacts or any objects that looked to originate from the Bronze Age period. In fact, the earliest finds only appeared to date late 17th or 18th century. One thing I have noticed is that from time to time fragments of giant stone slabs have come to the surface that that farmer has had to manhandle to the side of the field. I have often wondered whether there had once been a prehistoric or Bronze Age settlement in the area and, if the people buried their dead in stone cists, whether ploughing had broken them up and scattered their remains over the fields. In my searches I have also picked up pieces of pot shards of white gritty form that look to be medieval or earlier in origin; however, I have found nothing in the form of associated metal artefacts that could help date the pottery. On another occasion I was surprised to find a human tooth on the field’s surface. I have no way of telling how old this is, but I have kept it in my collection.

Older Than Georgian?

When using the Viking VK 40 just before Christmas I came up with a number of strange objects that I encountered some problems in dating. Could these be much older than my usual Georgian finds, or is it just wishful thinking? First on the list is a piece of thin copper alloy metal in a brooch-type shape. It shows faint traces of decoration on the front, and on the reverse there are traces of what might have been a pin. It reminds me of some Roman brooches I have seen but I am dubious of the metal alloy for this date. The second find in this category is a piece of silver again showing slight traces of decoration. At one time it was a hammered and flattened circular piece and may even have been a ring brooch; however, there are no sign of where a pin may have been attached. When I dug this up it gave a good high number on the VK 40’s screen. Unfortunately, the find is buckled and there are no identifying markings such as a hallmark. From time to time odd coins turn up in this field. The VK 40 found two American Indian Head cents which, with an earlier example, makes three to have come from this field. Another strange artefact to be recovered by a friend of mine was a length of chain made of copper alloy and with large incised links. This was shown to another friend who thought that it might be part of a sword attachment chain. I wondered about the possibility of it being a fragment of chain mail, as I had never seen a piece of chain like it. I then found a piece of metal with a scratch resembling a cross on it. What was odd about this find is that, although definitely metal, it has a texture that reminds me of asbestos. Next on the list is a heavy cast metal pommel that is threaded and highly decorated. I believe it to have been made from brass and the decoration is quite exquisite.. Again I wonder if this find could be earlier than Georgian and could have been part of a weapon such as a sword or a flintlock pistol. My final mystery item is was a fragment of heavy brass or copper alloy that looked to be part of a tool. But could have been something more exotic such as part of a battle mace? Another suggestion was that it was simply part of the head of a soldering iron as there are traces of a silvery substance that could be solder.

All of the mystery items - apart from the length of chain found by a friend of mine using a Viking 5 - were found during the testing of the VK 40. The targets were indicated by easily defined high numbers showing on the screen as between 60-90, and were dug up at depths from 4in to 8in. The search mode used was Inland setting and All-Metal (rather than standard Motion or Non-Motion modes) with a constant background threshold noise, which I have found to be personally best for my sites in Scotland and my style of use.

Beach Appraisal

My beach tests of the Viking VK 40 were carried out on two types of beach: one a light shingle, and the other sand. With the extremely stormy January of this year - experienced up and down the country - I had expected the sand to be stripped off the beaches leaving great empty gullies and coins lying everywhere on the surface. However, as I was about to find out, if you lived on the east side of the country then the severe winds were blowing in the wrong direction and more likely to be bringing in more sand than taking it off. When visiting the old harbour at Auchmithie I noticed that this was the case, for the shingle was pretty much in the same position as when I had visited the site in normal weather. If the winds had been right, as on one occasion when I made a visit after a storm, a lot of the shingle would have been stripped off and normally non-detectable finds would have been available going right back to early Georgian times. Finds were plentiful in number but not in age, consisting in the main of fragments of molten or cut aluminium. On this particular beach the VK 40 worked well enough but seemed to be affected in the Beach mode by the mineralisation when the shingle was wet with sea water. I found that I seemed to be getting better results by switching back to the Inland All-Metal setting. But all beaches are different, and each can vary from section to section, so it is necessary to experiment to get the best performance from the make and model of the detector that you use. As well as the junk pieces of aluminium I was finding quite an amount of small pieces of copper and brass but - surprisingly - not the coins or fishing weights that I had half expected to find. Auchmithie is an intriguing harbour having its associated village set high above the cliffs. There are plenty of tales about smuggling here, and its treacherous rocks have resulted in shipwrecks from all ages. An article in the Arbroath Herald from the 1970s covered an incident back in the late 19th century when it was believed a wreck of medieval date gave up part of its cargo. It was said that after a storm thousands of hammered coins - some going back to the 15th century - were strewn amongst the rocks. I have always hoped that I might be able to find at least one of those lost coins after a storm, but so far I have been unlucky. The next beach we visited was sandy and much closer to home. Whether the wind was in the wrong direction or not, I hoped that the turbulent weather would have at least stripped some of the sand off to reveal the shingle that I knew to be underneath. Once again I was disappointed for the beach had a much bigger build-up of sand than normal, some of it being feet deep in places. Not only had the storm brought in extra sand, but there was also a lot of pollution in the form of seaweed and even tree branches. Despite these problems we conducted our search and recovered about 30 coins between us - all modern. As stated earlier, all beaches are different, but once again I found that the Beach mode was not as sensitive as the Inland mode/All Metal, especially over wet sand. However, in my favoured search mode with constant threshold the VK 40 was quite at home on the dry sand and - despite the unfavourable conditions - I managed to find over a dozen coins in an hour’s search, as well as a bunch of keys that some poor unfortunate had managed to lose. One thing I did notice was that the VK 40 gave a poor audio response to rusty post-1982 1p and 2p coins. This is not really surprising as they are debased and have an iron core with a thin copper coating. In contact with sea water, and with the effects of electrolysis, this coating does not tend to last very long in the case of beach losses. As a result they will give a signal that tends to jump about but - as you all know by now - all “iffy” signals should be dug. The following Sunday saw me on another beach in Fife showing a friend of mine how to work the Viking VK 40. I left him to try the detector for a while and the first good signal he received was a 1944 shilling in very good condition. Unlike our modern iron-cored “coppers” the coin looked as if it had just been lost, and he was very pleased to have found it.

Conclusions

During testing I was impressed by the Viking VK 40’s performance. I found it to have excellent discrimination abilities, and very good sensitivity that provides good in-ground depth. On the beaches I tested it on, I found the VK 40 to have limited abilities on wet sand; however, I found it to work as well as any other detector I have tried over dry sand. On inland sites this detector is very much at home, although its computerised discrimination read-out occasionally gave conflicting results on the screen. This seemed to be the result of the detector being fooled by large deep iron of particular shapes - targets that represent problems for most detectors.

Viking have come up with yet another great detector. Introducing the membrane key pad is a right move as it does away with rotary controls completely. I have not yet finished with my findings and will include the performance of the VK40 on beaches in a future issue (when the present foul weather allows me to search some!). I preferred to use the All-Metal mode with its background threshold on most of my sites, and therefore have not really used the Motion and the Non-Motion modes much as yet. My only real criticism of the VK40 is that I would have preferred the search coil to be a plug-in type as opposed to it being hardwired. This would have allowed the detector to be broken down more easily for transportation. The detector is very easy to operate and offers good discrimination and great depth. It is well balanced and light enough to use all day; it therefore should appeal to all newcomers to the hobby as well as the more experienced.

Specifications

Model: Viking VK40

Type: Microprocessor Controlled, All- Metal, Motion and Non-Motion, LCD Target Display, Variable Discrimination,

Sensitivity and Pinpoint via Membrane Key Pad.

Batteries: 1 x PP3

Battery Life: 10 to 15 hours using an alkaline

Search Coil: 9.5in concentric coil

Weight: 1.4kg

Accessories: Coil cover, headphones, detector holdall, control box cover.

Price: £229.00 including U. K. Vat.

Guarantee: Two Years.

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