THE NEW SURFMASTER PULSE TEST REPORT.
By Alan Hassell copyright 19/2/93
When a person has dedicated their life to shallow water metal detecting, it's little wonder when a new product becomes available that their curiosity to try out the new product takes precedence. White's Electronics U.K. developed their first Pulse induction metal detector about ten years ago in Inverness, Scotland. That unit was the highly successful P.I. 1000. Because of its ability to penetrate deeper into the wet sands and recover gold rings lost by swimmers its success was assured.
Many of these units are still being used after giving years of reliable service to their owner's. Continuing development by White's research teams, produced the P.I.2000 and later the current model the P.I.3000.
Each of these new machines had improvements over existing models. The new Surfmaster Pulse is the result of over eight years research and development by White's technicians, who's goal it was to match the speed, sensitivity and ease of operation of an induction Balance, VLF machine without responding to wet salt and black mineralized sands.
And detect those left-behind targets missed by other detectorists. The Surfmaster Pulse, is perhaps one of the few machines that was purposely never released into the market place until it had been tried and tested in some of the hardest to detect beaches in the U.S.A. Older P.I. detectors worked on 3.5 khz and had to be continually retuned when crossing channels, in order to maintain maximum depth and sensitivity.
The Surfmaster works on a higher frequency 6 khz with faster pulse rate. Most of these earlier P.I.s utilized VCO or siren type of audio tone systems that either increased in the clicking (pulse) rate or changed from a threshold tone to a high pitched squeal when a target was detected.
What White's development team were attempting, was to produce a Pulse induction metal detector which responded similar to a VLF type machine. Mainly because of the numbers of individuals becoming interested in shallow water metal detecting and the need for a similar sounding machine, that detectorist's had become familiar with on land. The Surfmaster is the first P.I. machine that has the old familiar 'BEEP' signal. What they finally produced, can only be described as a remarkably innovative shallow water metal detector.
FIRST IMPRESSIONS.
Overall the design and appearance of the Surfmaster Pulse, matches that of the Surfmaster II which was a VLF produced for fresh water detecting and had discrimination features built in. This unit was not introduced into Australia, although it would have been ideal for lakes and rivers used as swimming area's. However, the Surfmaster consists of search rod, coil and control box. What is unusual is the fact, the control box can be mounted onto the search rod in several positions or alternatively used hip mounted, adding to versatility. A 6 x 4 x 3 inch Ikelite underwater housing has been used for the control box, which consists of two parts, top and bottom sealed with 'O' rings.
The top of the control box being clamped to the bottom with stainless steel clips. The top section being reinforced with stainless steel running along the edges adding extra strength to the sides of the Perspex case. Sufficient pressure is exerted by these clips to provide a waterproof seal. However, like all submersible detector's care must be taken when closing the case to ensure it is seated properly before clamping.
Improper assembly of the case could result in a leak and may damage the detector. Therefore, it pays to make sure the top is seated properly onto the 'O' ring before clamping the case completely. Although, it is not mentioned in the instruction manual, which is quite comprehensive and easy to follow.
I prefer to use a liberal smear of Silicon grease on 'O' rings as this ensures a watertight seal is obtained and reduce possibility of leakage. Prevention is always cheaper than the cure and possible down time especially if you use your detector frequently. White's have even printed sealing instructions onto the cover together with simple easy to follow tuning instructions, for beginners.
There are only two external controls. (1) Rotary on/off pulse delay control and (2) combined tuner and battery check control. Waterproof Piezo electric transducer headphones fitted into Bilstrom Ear Protectors are supplied as standard equipment and are factory sealed into the control box.
The coil is the new half inch thick 9.5 inch Amphibian hole in the centre loop. Used in clear water, this hole is an extra aid for locating the target once located. The coil is fitted to the search rod with a special non conductive nylon nut and bolt as is usual with most P.I. detectors. C.A.D. or Computer Aided Design has obviously been used in the design of the printed circuit board owing to its small size about 75 mm X 55 mm.
Modern high tech electronics employ miniaturization techniques to reduce weight. One only has to look at the computer industry to realize modern hand held computers are just as powerful as those used in the office. Everything is getting smaller, more powerful, and sophisticated, including ICs or integral circuits. Some of these ICs were specially designed and manufactured specifically for the Surfmaster.
We forget, years ago they used vacuum tubes, which were replaced with transistors, that in turn were replaced with I.C.s. As technology advanced, things got smaller. Maybe one day, the P.C.B. of a detector may be no larger than a postage stamp, who knows, that's technology. Fully assembled, the Surfmaster P.I. is light enough to use all day without fatigue.
CONTROLS.
The Pulse Delay control is used to turn the detector ON and OFF. It is also used to select the level of non-ferrous trash rejection similar to a discriminator on a VLF machine. It cannot reject nails, but can be used to reject a variety of junk metal items including steel bottle caps and ring pull tabs at its highest levels. Under normal circumstances, you should dig every signal if you want to find gold rings. P.I. discriminator's are not capable of the same amount of discrimination as VLF detectors. Using the pulse delay in higher levels could result in a 50% depth reduction. A pre-set position marked (P) is the level suggested by the factory. In some area's of highly concentrated Black mineralized sands some ground noise and false signals might occur. This noise can be reduced by advancing the Pulse Delay slightly. There could be times when you find yourself working an area littered with aluminium foil torn from drink cans. By advancing the Pulse Delay, you can ignore these signals, but at the expense of loosing some other targets.
TUNER, BATTERY TEST CONTROL.
This control is used to adjust the threshold tone to a level which can just be heard. A slight trembling or sputtering sound is normal. It is essential to keep the threshold tone as low as possible as set at higher levels it could mask out some of those deep hard to find targets it was designed to get. Setting it in the silent mode will reduce depth but eliminate noise from nearby detectors and electrical sources.
White's could have pre-set the threshold control, but no two people hear the same things. Sometimes, if the noise of the surf is too loud it helps to turn up the threshold in order to hear it. The Tuner control, also doubles to check the state of the batteries. These are checked by turning the tuner control to the left until a click is felt, similar to turning the detector off. When the Pulse delay switch is turned on a loud tone will be heard. As the batteries lose their power the sound of the tone gets lower. Weak batteries will cause erratic signals, instability and noise in the detector.
BATTERIES
The Surfmaster is powered by eight AA penlight batteries, standard carbon zinc batteries will last approximately 15 hours. Alkaline Batteries are recommended and should give between 25 to 35 hours of continuous operation.
INTERNAL CONTROLS.
The circuit board contains three variable resistors, two are factory set when calibrating the circuit and are marked with red paint. These should not be touched under any circumstances as it will seriously degrade the performance of the detector. They are set at a premium and instrumentation is required to reset them. The third variable resistor is used to set maximum volume in the headphones. It is easy to set, remove cover and install new set of batteries. Place headphones on head, turn power on. Wave large metallic object near the coil to get a signal and adjust the volume control until the signal is loud but not intolerable. This might need re-adjusting as the batteries diminish in strength, and also when noise of the surf makes hearing difficult. The volume setting has no effect on battery life.
TESTING THE SURFMASTER.
Pulse Induction metal detectors do not suffer from capacitance effect, the same as it does with VLF machines. Because salt water is a conductor and actually increases the depths attainable with Pulse Inductance machines IN AIR tests cannot be used as a guide. Simply because when used in the field they detect targets deeper than they would in air.
So the problem is, How does one test a machine such as the Surfmaster.? Without instrumentation, used by electronic engineers, to make comparisons it would be no easy task. However, there is another way, that is Test by Comparison of other detectors already in use, such as the 1000, and 3000 series.
The 3000 being an upgrade of the superseded 2000 being the better choice. No one person could really do this by himself so I called on the assistance of long time friend Jack Bosanquet. I introduced Jack to Shallow Water Metal Detecting many years ago and he has become a leading authority on the subject in his own right.
His knowledge and past experiences would be beneficial to enable a fair and just assessment by comparison of the Surfmaster against two other machines. The idea was quite simple, Jack would find a target with his 1000, this would be checked with the 3000 and then the Surfmaster. Then the target would be dug up and retrieved.
Finally use the Surfmaster to locate a deep target to see if the other machines could or couldn't match its performance. Believing a test such as this had never been attempted before, it would prove at least one thing, which machine equalled or outshone the others.
They were after all manufactured by the same Company and are stable mates. Finally after several days of surf caused by high winds, we got that break in the weather and were able to get into the water. Working with three detectors isn't the best between 2 people.
Every target that Jack located with his PI 1000 could be located by the 3000 and the Surfmaster. Testing can be a long drawn out procedure as each machine had to be turned off, while another machine checked the target. Placing the P.I.3000 on my floating sieve I finally started out with the Surfmaster by myself, in order to find that hard to find target. Eventually that hard to get signal was discovered and neither Jack or myself could locate that target with our machines.
Because there was some swell running at the time, try as I might I could not relocate the target a second time, although we both heard it the first time. I was very impressed with the self adjusting threshold, as this allowed me to travel back and forth across the channel without retuning the unit.
The signal given off by the Surfmaster is quite different and cannot be described as a bleep, but more like a DAH, if you've ever done Morse code. It's a sharp, clear, narrow type of signal ideal for pinpointing. Although the coil must be kept in motion for the Surfmaster to respond to the target. One thing I did miss, was the pinpointing feature on the 3000. Which allowed the signal to be heard when digging a target.
The Surfmaster tunes out the signal when the coil becomes stationary. The hole in the centre of the coil, does assist in assessing where the target might be located, it is easier to pinpoint than the other machines. Both Jack and myself would have preferred a non buoyant coil than the one supplied. Although, this is ideal, very light and easy to use on wet sands for long periods of time. In water force had to be exerted to get the coil onto the bottom.
Once a target had been located, you released the detector, the coil would bob straight up to the surface and the control box would sink to the bottom. The control box can be made buoyant by simply using some insulating tape and a piece of polystyrene placed at the bottom of the control box, or under the arm rest. Numerous targets were found during the test including coins and a 3 grams 15 carat wedding band at a good depth.
The Surfmaster Pulse is on a par with both the 1000, and 3000 series, and might even have an edge on them with sensitivity. On wet sand it will respond to signals, ignoring salt water and black mineralized sands, no matter how fast you swing that coil. This in itself is a major breakthrough with Pulse Induction.
It is a highly sensitive machine on land or submersed in water and is capable of finding gold rings lost in water. The Surfmaster is a reasonably priced unit, making Pulse induction affordable to those detectorists wishing to enter the lucrative field of shallow water metal detecting. In January, 1993 Geoff Mackrill and three friends from the Chalfont St.Giles metal detecting club took a water detecting trip to Spain.
They took with them 3, Fisher 1280x machines, 1, PI 3000 and a Surfmaster Pulse. On the second day The only machine that recovered anything was the PI 3000 used by Geoff Mackrill. The 1280s were unable to penetrate the sands. On the 3rd day it was decided to split into teams of two. One detecting, locating targets, the other digging them up as they only had two PI detector's between the four of them.
The Surfmaster Pulse was reluctantly put into use because it was a new machine and its owner had no experience with it. Almost immediately the Surfmaster started to find and recover goodies. One day, one team recovered 11 gold rings, over 100 coins and only 15 pieces of trash.
At the end of the week 79 pieces of gold, consisting of rings, medallions, chains and ingots were recovered together with heaps of silver items and 1000 s of pesetas. The coins alone paid for their air fares and hotel accommodation. These were members of a detecting club in England I had lectured too on shallow water metal detecting.
Detector dealers sold several members VLF type underwater metal detectors that are the wrong machines for penetrating deep sand but ideal for lakes. They now realize that they made an expensive mistake in their purchases. They also now realize that Pulse is not only far superior, they get results. Those 4 guys and others who witnessed the display of the finds at a club meeting following their return, are planning another visit to their El Dorado in Spain, all equipped with PI machines, hoping to reap a much bigger harvest next time.
HAPPY HUNTING. alan hassell by the way this is a very old article
Linkback: You are not allowed to view links.
Please Register or Login
http://www.thunting.com/smf/index.php/topic,10367.msg65269.html#msg65269
|
|
Logged
|
|
