Handheld GPS units

[ba229]

Have thought about buying a GPS unit so that i can mark my favorite fishing spots to find them easier.

Because i only have a 12ft tinnie and already have the sounder i was think handheld GPS units.

Garmin have 2 cheap models out at the moment, the eTrex ($220) and the Geko ($200-$250).

How accurate are they?

Does the unit need to be able to read DGPS for accuracy?

What does "position format: lat/long, UTM/UPS, MGRS, loran TD's etc" mean?

what does "accuracy position:15 meters RMS mean? ie the meaning of RMS

and one last one what does "interfaces: RS232 with NMEA 0183, RTCM 104 DGPS" mean?

I know the guy in the shop will tell me but i want to hear from someone who ISN'T trying to sell me the thing.

Regards
Alex

[FishFinger1977]

Nmea is the protocol or software standard the unit uses to communicate with other devices like a matrix sounder or what not. They are as accurate as any other unit as they are subject to the accuracy degradation (random error)put in by the us dept of defence so bin laden can't put a missile up georges butt. The accuracy is however much better when a war is on as the error is taken out, all units display an estimated postion error in meters.

DGPS won't be here until about september so i am told but it only limits the error down to five meters or so from anywhere to 100 at the moment (it should be noted though the error is mostly with altitude not so much the distance over ground). The etrex is good but you should get one with a marine nautical navaid database in it (All beacons are displayed with a description of what colour and flashing intervals the lights are)

You really need one with a good plotting system in it and the ability to zoom down to 20-30 meters at the least as this will help get dead on the marks. Position format is the way the numbers are displayed this is important to be set right as anyones marks may not fit in the required field, also most people use wgs 84 I think and it should be set to that as well any other format will be a little out from other people as well.

I recently bought the GPSMAP 60c which has 256 colour and all the bluecharts from Sydney to above Rockhampton and I will never go back to anything else, handheld is the way to go i reckon as i hike a bit as well and the mobility afforded by them is unreal. Blah blah blah I think I have said enough, have fun mate ;)

[blaze]

Hi alex
I have two hand held gps's
a garmin etrex, nice unit and has every thing you would need, to mark fishing spots, find ya way back in the dark etc. if you buy one get yourself a set of rechargeable batteries, and a spare set.
the other one is a meridian platium, this unit has mapping ability and lots of other things, cost of about 1k with a map
i prefer the etrex in the boat
cheers
blaze

[Mudcrab]

DGPS died a natural death some years back when the Yanks released many defence satellites to the commercial/recreational market. DGPS relied on a land based transmitting station such as the 4KQ one on St. Helena island. The old error of about 100+ metres was there simply because the atomic clock in the sats, with a maximum error of one second every 20,000 years, could nonetheless be adjusted by the Yanks (like about .0005 of a second) and thus deliberately inject an error into the receiving antennas. This was to hopefully stop the baddies using the sats from lobbing bombs and missiles around too accurately. That type of technology is now old hat and with some 26+ sats now reliably in operation, the maximum error should now be only a few metres. About 75% of the cost for a GPS is in the antenna. Bigger is better! Handhelds are OK if you have eyes like a falcon and can see the little digits in the dark, on rainy night and when the batteries start to go flat. In a rough sea you will get eyeball bounce and won't be able to read them anyway. Also a good way to hit another boat or a beacon maybe as you are looking down at the GPS trying to work it out. I personally reckon you are better off with a console mount right in front of you and orientated the way you are heading. Also most handhelds are not waterproof, they will sink and rely on AA batteries. Put the integral light on and you will suck the batts dry very smartly. Some guys like them and and that is great, I find using them similar to milking a mouse! Too fiddly!

[ba229]

thanks for the feed back guys.

Blaze, what sort of accuracy do you usually get with your etrex?

FF1977 i had a look at the GPSMAP60C yesterday. what an awesome unit. just a bit :o out of my budget unfortunately, otherwise i would be holding it right now.

[blaze]

best, 5 metres, i use it to come home in the dark up the river and have not hit bottom YET, the channel is only 5m wide in places and very poorly marked
cheers
blaze

[SeaHunt]

There is plenty of technical info on the web about how they work..
I have the Magellan Meridian Marine handheld, waterproof and floats, I recon its accurate to about 3 metres. Comes standard with all the Nav becons for Australia, has basic mapping, backlit screen for in the dark. And it even tells me which major road I am on in Australia. Can buy more street or Nautical maps if you wish.
I think I paid $800 back when. Could be cheaper now. 2 AA batteries last about 18 hours without the backlight on.. Digi Cam also uses AA's so I always carry spares in the boat glovebox, and they are not that dear if you can nick em from work ;)
Have a go at this.
http://www.magellan.com.au/marine/product_display.htm?part_number=GPSMAGREC7200

[bigbrian47]

I've had a lowrance h/held global212 for a few years takes 4AAs @ use a cig lighter lead in the boat @ in the 4wd in the bush i use the ram mount in boat @ vehicle @ absolutely happy with it
recently bought @ navman 5500 colour gps for the boat @ so far happy with it
cheers brian

[Kerry]

With accuracy probably more important thing to be aware of is, what the accuracy "can be" more so than what it normally is. Generally less than 20 metres the majority of the time, normally less than 10 metres most of the time, generally around 7 metres or less some of the time but can also be more (much more in fact) than 10-20 metres at times. #

Standard Positioning Service (SPS) Signal-In-Space (SIS) world average accuracy is less then 13 metres 95% of the time and less than 36 metres based on worse case scenario. So there is also the other 5% unknown, which is exactly that unknown, so one should not assume accuracy will always be guaranteed.

SPS is what every recreational receiver currently receives so really (in theory) one make/model is not anymore accurate than the other as accuracy also relies on many other variables including the user and some factors are controllable, some not. Accuracy can and does vary from place to place, from day to day even from one minute to the next for a variety of reasons.

The one type of accuracy that simply doesn’t/can’t occur with GPS is the ones who always get within a few feet, even a few metres, simply doesn’t work like that, not 100% of the time, not even half the time.

DGPS these days (since Selective Availability was discontinued) has more to do with integrity than pure accuracy as for general recreational/boating purposes dGPS is not an absolute necessity. dGPS does provide an improvement #in accuracy but it is the capability of dGPS to detect errors in real-time that make it useful in critical navigational applications.

A GPS without augmentation (such as dGPS) has no real way of knowing if errors exist in the signals so these undetected errors can cause erroneous positions a ttimes. #

DGPS certainly isn’t something of the past and currently forms an important and integral part of marine navigation requirements in Australia. For recreational use dGPS really isn’t a requirement in most vases but it is available, free to air but requires a differential beacon receiver to take advantage of the improved accuracy and integrity.

Position format:

Lat/Long is generally a degrees type format with lat(itude) being North/South of the equator. Long(itude) is East/West of the 0 degrees, which is approx Greenwich England. Lat/Long might look something like 35 34.534’S, 155 23.834’E (dDD MM.mmm' Degrees Minutes. decimal minutes). Lat/Long could also be in decimal degrees, Degrees Minutes Seconds etc.

UTM/UPS is basically the projection of Lat/Long and might look something like 680234.1E, 7450000.4N Zone 55. As zones are only 6 degrees wide the same coordinates can exist in every possible zone, so one must always include the zone number and for that matter the Datum as identical coordinates in different datum’s are different physical points on the ground.

MGRS is a military grid system, don’t worry about it.

Loran TD’s relate to an antiquated terrestrial navigation system, pre GPS days that has managed to remain functional. Basically doesn’t exist in Australia, not all that accurate (compared to GPS) so basically forget about it.

Accuracy as 15 metres RMS. Root Mean Squared means accuracy will be less than 15 metres approximately 68% of the time.

Another one you might see is 15 metres CEP. Circular Error Probable, which means 50% of all positions, will lie within a circle of 15 metres radius.

RS232 with NMEA 0183, relates to the National Marine Electronics Association communication standard 0183, of which there are several versions, which allow electronic devices to simply communicate with each other. Such devices could be GPS, depth sounders, autopilots, VHF radio, Loran, Weather instruments etc. #

RTCM 104 is also a communication protocol that differential beacon receivers use to transmit/receive differential corrections.

#

As for some of the other misconceptions – there is no accuracy degradation (as such) and hasn’t been any degradation of accuracy (previously known as Selective Availability) with GPS since SA was discontinued back in May 2000. Forget all the rumours and speculation about what occurs with GPS accuracy each time the US looks towards terror issues as there simply has not been any reason to degrade accuracy or any future plan to degrade accuracy to previous pre May 2000 accuracy limitations. Simply hasn’t occurred.

There has been no accuracy degradation pre/post or any side of any war since SA was discontinued May 2000, no need, as there are now other non intrusive civil means with respect accuracy to achieve military goals.

DGPS (as installed by AMSA) in Australia has been an ongoing AMSA project since 1994 and in no way should AMSA's differential be confused with WADGPS (Wide Area Differential GPS) systems like WAAS. WAAS type differential will not be available in Australia any time soon or for that matter any time in the future. WAAS is only relative to America and specifically North America so do not buy a receiver based on WAAS capabilities, WAAS simply doesn’t work in Australia.

Handheld, fixed mount, mapping or whatever comes down to ones personal requirements/needs as there is no one unit that suits all purposes.

Cheers, Kerry.

[subzero]

And that was the short version :o ;D ;)
Shite, where did you learn all this stuff Kerry?
We might have to get you down to the base to run a course for us. :)
Cheers Lloyd

[Sportfish_5]

Kerry - Thanks for that excellent info. Did you write the 4 part article that was in F&B a while back about GPS?


Cheers

Greg

[Mudcrab]

Me too Kerry! Well written!
Some of the new GPS Units no longer come with "DGPS equipped" owing to the costs of the additional receiver needed. The standard GPS receiver has the capability of rejecting any satellites with a problem that may affect the accuracy i.e garbage in = garbage out! These are termed "healthy" or "unhealthy" satellites. Fortunately your GPS knows the difference. On many of the older GPS models, it was possible to override the GPS brain and force it into accepting an "unhealthy" satellite. This was more common in the days when you only had a very limited number of usable satellites and even an "unhealthy" sat was better than nothing. Surveyors get almost a zero degree of accuracy but have specialized GPS receivers (so my mate says!) that intergrate ground radio stations. Their readouts may be similar to: S 27.252.25647 (the latter being ten thousanths of a "second". Gotta get me one of them!

[ba229]

Thanks Kerry,

i was hoping you would pick up on this thread as i knew you were the GPS man.

i went back over two years of posts and you seemed to know what was going on.

i'm really only looking for a basic entry level GPS unit so i think i will go with the Garmin eTrex. just got to find the best price now.

regards
alex

[nonibbles]

I have a magellan 315 handheld gps and it suits my needs. I use a console mount to snap it into place on my console and used the cigarette lighter wire to hardwire it into the boats electronics with a toggle switch to isolate it from the battery if for some reason I wish to run down the internal batteries. I then use the datasend software that I bought with it to upload/store waypoints in different areas (eg: TSV, hinchinbrook, ayr to bowen) that way I just carry the waypoints and routes for the area I'm going to and all the useless ones stay at home. It zooms down to 10m and is supposed to be accurate to 3m on its best day. Of course this depends upon the error applied on the day the waypoint was set and the available satellites at any given time. I have yet to have to search for the exact location I was in before because most spots have a fairly prominent feature that I reference in the comments section. The GPS I use is not flash but in conjunction with the not so flash sounder its all I need at present. As I said, this suits my needs (I have a 5m open runabout).

[Kerry]

Kerry - Thanks for that excellent info. Did you write the 4 part article that was in F&B a while back about GPS?

Does sound familar, that last version (2003) was basically a re-write/update of the original series printed back in 1998.

Cheers, Kerry.

[Kerry]

VMR V.Point

May not be “differential equipped”, not many are as standard but there’s also not many that are not “differential ready” but do require an additional beacon receiver but then accuracy does cost, the more the required accuracy/integrity the more one should expect to pay.

NO, a standard GPS does not have the capability to reject problem signals (by itself) in real-time and erroneous signal errors will affect position accuracy until the control centre actually detect inconsistencies and then set the problem satellite/s as “unhealthy” as part of the broadcast almanac and then the receiver has to download this information, which doesn’t happen instaneous. Unhealthy satellites are simply ignored (and for good reasons) by all receivers but there’s no recreational standard GPS receivers that can really detect problems before a satellite is set unhealthy as the following highlights.

http://www.cqnet.com.au/~user/aitken/gps/gps%20the%20other%205%20percent.htm

Basically the above was an issue with one satellite that went ape over Oz early 2004 but could not be detected and went undetected by the ground stations for many hours and hence positions were affected rather severely until the control centre set this rogue sat as unhealthy. Satellites on maintenance (basically occurs on a daily basis) are also set unhealthy while maintenance and re-positioning occurs so as not to affect positions.

An unhealthy satellite is not normally something to override and one does opt to use/override an “unhealthy” satellites at one’s risk but fortunately most recreational units don’t make this capability a user option (for very good reasons).

Survey receivers are not really something different and simply can’t achieve accuracy without some form of augmentation (additional receivers etc). Survey grade receivers basically use the same signals it’s just the way the data is used/manipulated that makes the difference. Survey receivers zero degree accuracy? Not really as accuracy depends on distance and/or time. Real-time accuracy is limited to distance and long distance accuracy require quite lengthy data recording periods.

As for #“ten thousanths of a second", well if anybody wants to get into what’s involved in trying to achieve 0.00001” (0.05mm or roughly 2 thou, very little in fact) then we could discuss it if anybody really wants to #:).

Cheers, Kerry.

[Kerry]

.... i'm really only looking for a basic entry level GPS unit so i think i will go with the Garmin eTrex. just got to find the best price now.

The best I'm aware of is around $220 so if you find one less then that's a bonues.


Unrelated but recently seen some speculation that simple standalone handhelds will be able to achieve cm accuracy in the not too distant future, like next year (2005).

All PR BS, not true, can't happen, won't happen not in that time frame anyway and not to cm accuracy BUT as a prediction I'll be brave enough to predict sub decimetre (less than 0.1m or 4") without augmentation by 2012, just a few more years (plus) to wait but #;D

Before that probably less than about 1.5 metres by 2008/2009 ???

Cheers, Kerry.
#

[ba229]

Heres one more question (that may seem obvious).

if the accuracy on the unit says 10m does that mean that the true position could be 10m to my left or 10m to my right or 10m behind me etc?

cause this in actual fact could have me 20m away from where i want to be.

try and follow me here. lets say if i am 10m away from the stop i really want and head left 10m but the spot is really to the right i would have gone in the wrong way 10m. thus i would now be 20m away from the spot.

am i being stupid? expecting too much out of GPS or is this a valid point of interest?

[ba229]

Heres one more question (that may seem obvious).

if the accuracy on the unit says 10m does that mean that the true position could be 10m to my left or 10m to my right or 10m behind me etc?

cause this in actual fact could have me 20m away from where i want to be.

try and follow me here. lets say if i am 10m away from the stop i really want and head left 10m but the spot is really to the right i would have gone in the wrong way 10m. thus i would now be 20m away from the spot.

am i being stupid? expecting too much out of GPS or is this a valid point of interest?

[Kerry]

am i being stupid? expecting too much out of GPS or is this a valid point of interest?

No this is a valid point in understanding GPS accuracy as basically accuracy affects the marking of the waypoint in the first instance then also affects the finding of the waypoint at some time in the future.

try and follow me here, Now your turn ;)

Waypoints acquired by GPS due to the effects of many variables controlling GPS accuracy could represent locations generally within about 15 metres (or less most of the time) but in some instances also further away from the actual physical position of the GPS receiver.

If by chance the waypoint coordinates equals the actual real world “truth” position (this fact will be rarely known at the time anyway) then in returning to this position this can be related to the current definition of “Positioning Accuracy”, as the waypoint position would be classified as a position of “truth” but the likely hood of this happening is extremely low with a recreational GPS.

While the GPS is at a specific location the recorded waypoint coordinates due to GPS accuracy limitations will actually define some other physical point on the ground (normally within say a 15-20m radius circle of your physical position 95% of the time). When one then attempts to return to what is in effect the original location (that is where the GPS was physically positioned previously when the waypoint was marked) the coordinates being used may physically define an entirely different point on the ground. The effects of GPS accuracy are two fold, once in recording the waypoint and once in trying to return to the same point with coordinates that physically define another point.

In other words say you sit a GPS receiver on your mailbox and record a waypoint, which we will call “mailbox”. Due to the effect of GPS accuracy the real world waypoint coordinates actually might be of the front door, back door, the neighbour’s mailbox etc. So you walk around the block and punch up the previously stored waypoint “mailbox” because that is where you want to go to, your mailbox. However the “mailbox” waypoint coordinates actually might physically define say the front door and so you are using the real world coordinates of the front door but really expecting to get back to your mailbox. All the while GPS accuracy limitations are again affecting your position this second time around. GPS accuracy also being the reason initially for the difference between the coordinates you really wanted (real world actual mailbox location) and the physical coordinates (somewhere else such as the front door) that were recorded.

In Pre Selective Availability days this type of situation/accuracy was known as "Repeatable Accuracy" (as opposed to Predictable Acucracy) and with your example of 10 metres the theoretical accuracy effectively is around 14 metres and not simply double at 20 metres.

Cheers, Kerry.

[ba229]

thanks kerry,

bought the etrex for $220 and have been madly marking waypoints for boat ramps and fishing locations.

i had coordinates for a ramp that i put in before leaving home. the coordinates had me no more than 6 m away. i am very impressed.

the thing was the coordinates i had were 2 digits for the seconds and the GPS unit i have has 3 digits so therefore i can get greater accuracy right? anyway have marked the centre of the ramp and will see today how close i get.

just for interest, i bought the unit from bias boating which is a chain of stores.

i have a map from waterways that has a GPS location on it to check accuracy. i put in the coordinates and headed of only to find the location was 250m from where the map said it should be.

both map and gps are in WGS.84.

went to coast guard to ask if there were any local spots that would verify the accuracy and they had no idea :(

went to a fishing shop they told me to go to for help. because i didn't buy it from them they didn't want to help. i fact they were VERY rude and it will take time for me to go back there for anything.

a customer there told me to go to the local yacht club. whole lot of blank faces there aswell :o

i didn't just want to beleive the map to tell me i had an accuracy problem so i headed to the boat ramp previously mentioned and was within 6m which is great.

therefore i think the waterways map is give false information.

will do some checking of this. the map does say it isn't intended as a navagational device but if they are going to give a datum point to check accuracy you would think it would be accurate information.

what i got out of yesterday is there is alot of people who think they know stuff but when you start asking questions that should be easy to answer you get utter studipity back :(

it seems kerry you are one of the few people that actually knows whats going on.

[Kerry]

The reaction your getting from some really doesn't surprise me #:-X


i had coordinates for a ramp that i put in before leaving home. the coordinates had me no more than 6 m away. i am very impressed.

the thing was the coordinates i had were 2 digits for the seconds and the GPS unit i have has 3 digits so therefore i can get greater accuracy right?

Greater accuracy? NO, not really but better precision and precision and accuracy are a little different. So with your 6 metres it does sound like there's some commonality (maybe?) in the datum/format BUT there's very few recreational GPS receivers with a precision of 2 decimal seconds and certainly none with 3 decimal seconds.

So just make sure that the GPS position format and the format of the coordinates/waypoints are the same.


i have a map from waterways that has a GPS location on it to check accuracy. i put in the coordinates and headed of only to find the location was 250m from where the map said it should be.

both map and gps are in WGS.84.

Now if you've double checked that the datum is correct then the other thing could be format accepting that is, that the map coordinates are correct? and at this stage one would have to assume the map coordinates are ok.

200 odd metres would have all the hallmarks of an incorrct datum, 250 metres ?? then could still possibly be datum but could also be confusion with position formats ??

WGS84 map and GPS set to WGS84? just double check to make sure, especially that the GPS is in fact WGS84 and not something like Astrln84 or Aus84 etc.

Incorrect position formats can account for an error in position of up to 800 metres, so make sure the coordinates you are adopting from the map match the position format the GPS is set to.

If the coordinates from the map look something like
30° 34.546'S 150° 23.106'E #then the GPS needs to be set to Degrees Minutes & decimal minutes.

Cooridnates that look something like this
30° 34' 54.6"S 150° 23' 10.6"E then the GPs needs to be set to Degrees Minutes Seconds.

Mix these two up and you certainly won't be where to are supposed to be.

Just because you might be showing only 6 metres away does not necessarily mean the actual coordinates are correct in a real world sense.

Cheers, Kerry.

[ba229]

the map is in degrees minutes decimal minutes like this 33 deg. 05.082 min.S 151 deg. 38.456 min.E

double checked map datum (on gps unit) is set to WGS 84.

on the units setup page there is variance of 012deg. E i take it that is set by the satellites cause i can't change that.

i think the error is in the wording of the map itself. and then the spot where they have put the "dot" on the map is also misleading.

[Kerry]

the map is in degrees minutes decimal minutes like this 33 deg. 05.082 min.S 151 deg. 38.456 min.E

double checked map datum (on gps unit) is set to WGS 84.

on the units setup page there is variance of 012deg. E i take it that is set by the satellites cause i can't change that.

On a marine type chart/map Degrees Minutes & decimal minutes as you describe should be the "expected" format.

As for the 012 deg that is changable (nothing to do with the sats) if you configure the variation as a "user" configuration then you can input a user defined value but most likely the default setting is "auto" and this is based on an internal lookup table, which is part of the software version.

From time to time most manufacturers update the variance lookup tables with new software/firmware releases.

Garmin releases new software versions for all their models from time to time. The latest/current software version for the standard Etrex is 2.14 (June 2002), which sort of says they haven't made any changes for quite some time ???

Just keep playing with it (you won't break it) as getting to understand what's going on won't happen overnight, but it will happen.

Cheers, Kerry.

[whiteman]

Kerry

Always interesting reading from you re GPS technology. I'm looking to upgrade my GPS12 cause I can't read the screen easily with my getting old eyes as it doesn't have the sharpness of new models. I'm still keen to get another handheld because I use the GPS on land as well as water. Current favourite is the Garmin GPSMAP60C - colour and charts.

If you were to spend your hard-earned, on a hand held, what features would you look for? Be model specific if you like.

[Kerry]

If you were to spend your hard-earned, on a hand held, what features would you look for?

Be model specific if you like. Now that would take quite some Research and then it would be difficult to base a decision like this around every model on the market.

But generically I would start at the map/chart end and also base any decisions on what I would/might do if I also wanted a fixed mount as the ideal thing is anything you have accepts the same charts etc.

This can be done but it might even mean involving different manufacturers.

So many many variables one could write a book about but obviously screen resolution is one thing and in this it is not simply the pixel count but how these relate to the screen size. Just because a unit has the biggest screen doesn't mean it also has the best resolution.

As an example a G-60C has a PPI of 109 (screen size 1.5 * 2.2) yet some of the E-trex's are around 141 PPI, which effectively is due to a smaller screen and also larger pixel count. As a comparison the GPS12 has a screen/resolution of 44 PPI, yet is identical in actual screen size (1.5*2.2) to a G-60C.

For mine must have external antenna capability and upload/download data support, external power in the 8-35 volt range but at least handle 12V direct and not have to reduce to 3V etc.

Mapping, yeah right, this simply opens up a whole new ball game. BIG decision trying to determine just what charting format you want to really get locked in too as there's probably more $$'s in the mapping (over time) than in the receiver.

Cheers, Kerry.

[whiteman]

You're correct on the mapping data front. But this is the way it should be as without up-to-date and accurate maps, what's the point of the hardware? Of course these maps (Townsville district at least) don't have the resolution to support you when you need to get below 100m but at least they'll help with visuals.

Can the base maps be maintained by the end user on a PC and reloaded for things such as adding green zones or movement of sandbars?

[Kerry]

Can the base maps be maintained by the end user on a PC and reloaded for things such as adding green zones or movement of sandbars?

No, manufacturers keep very tight reins on propriety formats, othwerwise users might have something useful and actually be able to swap different maps between any unit and actually achieve something that might be "standard" that the manufacturers would have little control over ;D

Once one gets towards the true PC based navigation systems then there is a lot more scope for including user defined features, lines, marks, shapes, colours etc. Still unable to modify/change the actual mapping but allows better overlay capabilities etc.


Cheers, Kerry.

[scubapro]

Hi Guys,

A friend of mine just bought a 12 Channel handheld GPS from Super Cheap Autos & is rapt int. All for $150-00.

Scubapro

[whiteman]

So all I need is to take the laptop and Capn Voyager out with me all hooked into the GPS! In a funny sort of way it might actually be cheaper than a colour hand-held except I'd need to invest in a bigger boat.

[Kerry]

That's about where things are heading, PC based systems. Most commercial boats these days are basically running a common garden variety Harvey Norman desktop with a nice LCD flat screen with SeaFarer charts.

And based on the cost of some of the top end chart plotters a PC based system can in fact be much cheaper and certainly more flexible.

Cheers, Kerry.