Photobuff

I haven't been out for a few years, but I always found it a wonderful puzzle. Finding some sites involved historical research, making CAD drawings from maps and laying in features that no longer exist and fooling with my metal detector. An FTF is always nice.

That circle sure looks like it held a benchmark at one time. I'd measure the diameter and see if it matches existing local BMs. FWIW, my luck with anything railroad related has been terrible around here. Tracks have been replaced or removed, and typically the BMs are removed at the same time. There's invariably new construction near the tracks and a fair share of marks are gone due to that. I notice the relatively new buildings in the background of the photos. Electrical stuff has been updated, so enclosures have been replaced or moved. My guess is the box and foundation were moved. I'm a bit surprised that anybody would set a mark in something as non-substantial as that box foundation appears to be, unless it was much better anchored at one time. My experience is that perpendicular dimensions such as listed tend to be very accurate and if the mark isn't where it's supposed to be, assuming streets haven't been shifted over the years, something bad happened. I think it was in that hole, but little can be proven and it has to be a not-found.

FWIW, I find the coordinates from USA Photomaps using Microsoft Terraserver to be highly accurate when compared to my GPS. Unfortunately that software and system are no longer updated, though I still find them useful for many purposes.

Well, the article is 54 years old and was a give-a-way from the company, but it's still under copyright so it wouldn't be proper to post a link. OTOH, if one were to click on my name and send me an email... Best, CH

Turns out I made that ancient metal detector article into a pdf file. It's from the 1950s in an application note from capacitor company Cornell-Dublier. The designs use tubes, but they give the coil designs (40 turns of #22 on a 1 foot diameter form) and operating frequencies. If one were to use a couple modern ICs to replace all the tube stuff, it wouldn't be hard to make the "pole type" detector and get several feet of depth. If anybody's interested let me know and I'll get it up on my web site. Size is 3MB. CH

So sorry- he looks like such a sweetie pie. We get so very attached to them. It's been almost two years since we lost our dear Dewey and I still think of him multiple times a day. Perhaps Rainbow Bridge has a benchmark where we'll all meet again someday.

I've happily used my Harbor Freight unit for several years and it works fine, but like all that type you're limited to a depth similar to the diameter of the search coil. If you allow for grass and rocks, that's not much. For the $25 on sale, I can't complain- it's found me several marks I wouldn't have found otherwise. As 68-eldo says, there are/were detectors that put the coils on each end of a pole, and those can go much deeper. I have some ancient articles on how to build them, but they operate at frequencies and amplitudes that aren't technically legal these days- too much radio interference because they operate quite a bit higher than the usual ones today. IMO, there are a lot of rip-off/snake-oil units out there for very high prices. I doubt they work much better than a simple design and a trained ear. Speaking of which, you get vastly better results if you use big old headphones that seal to the ear. Keeps out wind noise and saves batteries. What we all want is a cheap ground penetrating radar! Best, Conrad

There is a 1875 marker near here, again in/near a farmers field, so it's over 3' down. I'm 99% certain it's undisturbed, but just can't bring myself to dig a hole that deep without knowing I'm right over it. I tried for another one close to the first at the same depth, but couldn't use the old reference marks, so never found it. Someday! Congrats on yours.

Thanks ArtMan! My recollections are usually in the right direction, but the details can be a bit fuzzy. I should take up drinking so I have something to blame it on

They have a standard on this. It starts out something like HTT1 or 2, depending on the quality of the GPS unit and specifies how you should format the numbers. Hopefully somebody knows where it is on their site. I've done some in the past in decimal, but that's bad because DMS users might not notice and will make a mistake. Handheld consumer GPS units often produce their best resolution in the decimal format, so use that and convert before doing the NGS sheet.

Enter the coordinates on something like USAPhotomap. Around here, it's pretty accurate, but that's not always the case. The scaled numbers put the thing off the T intersection, but from the description, it's obviously on the west side of the main road. Go back with the tape and a metal detector that can detect non-ferrous metals and scan down a good distance of road at 27' from the centerline. Try to find out where the original cabin was- if you can measure from that, great. I doubt the road has moved much. If it's there, you'll likely find it, but my guess is the area was heavily improved since the '30s, and it's likely gone. If I'm really serious about a mark, I'll try to get old maps to confirm where the roads and buildings were. Sometimes things change more than we suspect!

I have one and it's great for what it was made for- hiking, walking, and anything where you don't need a map. I also have a Magellan 210, which has a darn good receiver, and the 101 is comparable under many conditions. IMO, the 210 is better under difficult conditions, but the 101 is no slouch. The 101 display is a bit easier to read and better set up for many things. Accuracy is similar, more dependent on available birds, than on the units themselves. The 101 uses a pair of AAA batteries, and I get a couple weeks out of a set of akalines for my morning walks. IMO, rechargables don't have sufficient capacity in the smaller sizes to be worth bothering with, though if you use it a lot and carry a spare set, they'll save you a few bucks. The wrist strap and extension for the 101 can be difficult to adjust for any practical size- it's too short without the extension, but too long with. I just carry the thing in a jacket pocket.

IMO, you should get a dedicated auto unit unless you have a riding partner. Using a handheld for trips is an invitation to crash. Then, for trail and such, get an inexpensive unit with no bells and whistles (live compass and barometer), like a Magallan 210 or various Garmin units. Be sure it has a PC interface.

As above, any detector is better than none. IMO, any cheap detector that can discriminate between ferrous and non-ferrous metal will do the job. Benchmark disks will usually be close to the surface, and will give a distinctive tone, compared to the screech of aluminum cans and tabs. The detector is less useful for things like copper bolts set in stone, though it will easily spot a mud covered disk in a cement culvert, in spite of the re-bar. Learning the characteristics of your detector is the most important trick, and personally I'd never spend much for one. I've been very happy with the very common one you can get for $35 or so on sale at Harbor Freight and such. The same model can sell for much more, so shop around.

Has anything changed in your computer? When I load the USB program from Magellan, it wipes out my SD/Compact Flash card reader. No doubt it could be fixed by going into the Device Manager and changing the port settings, but I haven't done that. AFAIK, the Magellan has more in common with an RS-232 device, than a true USB device, and the driver isn't a USB driver in the true sense. Someone who understands low level hardware can probably give a better description than that. At any rate, it's worrisome that the problem happens with several computers. You might try a full reset of the 210, and that's a good idea every few months anyway. The 210 accumulates a time error over a period of months (software bug), and mine seems to work faster and better if I do a full reset at least twice a year.

I've spent some time looking at this as well. Here's an interesting thing. I stay in D.DDDDD for the reasons mentioned above. Let's say I mark a spot and save it. My Magellan 210 saves the position as DM.MMM so if I recall it, the position will be shifted slightly. For maximum repeatability, I have to use the original D.DDDDD numbers, not rely on the stored waypoints!

I'm sure it's been in a hundred other posts on batteries, but go to batteryuniversity.com and absorb everything they have to say, remembering that NiMh and Li technologies are still changing pretty rapidly. Agree that several charge cycles are necessary to develop full capacity. Also, rapid charging may not get you all the way there- some amount of trickle charging is necessary, though in general NiMH cells should not be trickle charged for long periods of time. The self discharge rate of NiMh batteries is significant, so I always charge right before use if I know I'll need all the energy.

I just got a Fortrex 101 that I'm pretty happy with. No idea if it would be considered "old" or "new", as that model's been around a while. I had never seen it display WAAS until the other day, when I stood in just the right place in the backyard, and it picked up #33. The Ds come and go in some sequence, not all at once. Behavior seems to be a hybrid of the comments I've read above. It wasn't difficult to get the almanac loaded, and it didn't take long at all. IMO it all comes down to signal quality, which for the WAAS sats here in upstate NY, has been pretty terrible for the last year. The estimated error doesn't seem to change depending on whether WAAS is picked up or not. IMO, the reception is easily as good as my Magellan 210, and the large print is easier to read.

Aldi is just a sort of weird supermarket with oddball brands I've never heard of. I doubt you can buy anything on-line from them, as they don't even take credit cards in the store, only debit. I just picked up my 101 a couple days ago, and it's a great little unit. I'm starting to like it better than my Magellan 210, as the print is easier to read, the fit and finish are better, and under some circumstances, the reception seems better. Haven't tried to use the little serial interface yet.

I just got a Foretrex 101 today, and I think I like it better than my Magellan 210. It's sensitive, locks almost immediately (and I though the 210 was pretty good), seems accurate. The screens are easier to read for my aging eyes. The fit and finish is better. The local weird grocery, Aldi, advertised a "special buy" for $99.99. Why a grocery store would have these, I've no idea, but that's cheaper than Amazon, with no shipping to boot. I mostly hunt benchmarks, so don't really need a map, just good coordinates. And when I do need a map, there's the 210. What a great little unit!

IMO, the difference is negligible for all of us impoverished hand held non survey type GPS units, unless... your time is worth a nickel an hour, you've got $25, you've got a laptop computer, and the WAAS satellite gods are smiling in your area. Whacha do is download a copy of SA Watch, wire your GPSr to your laptop, and sit on the station for maybe 4-24 hours. After the program tosses the lower quality data, and averages the rest, you can get within a foot or so. The only trick is that your time window has to include a period where lots of satellites are available, and signal conditions are decent. There are many long periods where the quality of the fixes is quite poor, they tend to be off in the same direction, and no amount of averaging will help. This worked for me last year, but with the repositioning of the WAAS satellites the quality of my fixes this year has been abysmal by comparison. Not sure how good I could do averaging without WAAS, though it might be surprising.

Congrats all! Events beyond my control curtailed my BM hunting this summer, but wait till next time...

On the 210, lines on the right hand side appear to be normal power up junk, and nothing to be concerned about. I think they're less or non-existent when you power up using USB power, so it's probably surge current related. You might get different results depending on battery type and charge level. Of more concern is some vertical scratching on the LCD of my unit. It's obviously a QC problem with the LCD. It's most apparent with the back light on, but easy to see if you use a magnifier to examine the LCD under bright light. Basically, the pixels aren't perfectly square. Something probably rubbed the LCD glass during manufacture, damaging the pattern. It annoys me, but doesn't affect operation so I didn't bother to return it and suffer without the unit. IMO, QC should be better. IMHO, both Magellan and Garmin have a ways to go before claiming world class products.

Regardless of the answer, you may find this appropriate: Mark Twain: "When I was a boy of 14, my father was so ignorant I could hardly stand to have the old man around. But when I got to be 21, I was astonished at how much the old man had learned in seven years."

I've seen disks around here from the late 1800s, and though I haven't dug it up, I'm pretty sure we have one still around from 1875. Don't know about Maine though. The 1875 mark was next on my list, but my wife broke her arm, and I've had way to much to do to get out benchmark hunting. The blasted thing is also buried three feet down, so I want to be darn sure of the location before I dig.