Author Topic: Review of CST Berger pocket transit (compass)  (Read 7233 times)

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Offline PetrifiedWood

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Review of CST Berger pocket transit (compass)
« on: September 19, 2012, 07:05:35 PM »
Well as those of you who have been following the TOKT news thread know, I have been trying to locate some property corners at the new house. Anyhow, I decided a pocket transit would be a big help in finding them since I can get reasonably accurate bearings using one.

Anyhow, I decided to try a couple of different lower priced options than the $300 + Brunton pocket transit models. This CST Berger transit came in at $116 shipped from Amazon with my Prime membership.

CST Berger Pocket Transit

I also ordered a Brunton ball and socket tripod mount to allow the transit to mount to a tripod.

Anyhow, the transit arrived and was plagued with problems from the beginning. First and most obvious, the south end of the needle was painted red rather than the north end. This is presumably because the manufacturer assumes it will be used as a prismatic compass more than a transit. When using a pocket transit like this as a prismatic compass, you read the azimuth from the south end of the needle, which could be why they chose to paint it red. However for other modes of use you read the azimuth from the north end of the needle. In any case it's an easy fix with nail polish if you decide to do so.

the other problems with the compass were the bullseye level bubble was not installed properly. When the compass was resting on a level surface, the bubble was not centered. And finally the needle, graduated ring, or pivot were misaligned. This caused a situation where the South end of the needle would point to 180 when the North end was at 0, but when you turn the compass around so that the south end was pointing to 0, the north end was a few degrees off of 180.

Anyhow after messing with it for a couple of days I decided to return it and see if a replacement would be any better. The replacement came quickly (Yay Amazon!) and it is apparently much better. The needle reversal error the first one had is no worse than 1/2 of a degree (30 minutes of angle). This is satisfactory for my purposes. Neither compass came with a good instruction manual. Manuals for the Bruntons can be downloaded and since this is a copy, most of the operations will be identical.

Here is a link to the Brunton manual:

http://www.kooters.com/pdf/BruntonTransit-inst.pdf

The Brunton ball and socket mount is a bit loose on both the first one and the replacement. The slots on the sides of the body for the mount are not cut to the same dimensions as a Brunton so you need to shim them with a couple of pieces of thin cardboard to get a firm mounting.

The needles are balanced for the northern hemisphere and are induction damped. It appears to have two AlNiCo magnets glued into clips on either side of the needle.

In short, the new compass is probably a good deal for someone who wants an affordable option at about 1/3 to 1/4 the price of the real thing. But it's anyone's guess as to whether they will get a good one or a lemon. My suggestion is to buy from a place like Amazon that makes returns easy so that you can send it back for replacement in case it doesn't work right, and make sure to check it out thoroughly when you get it.

I have a real Brunton Com-Pro on back order, and a really cheap ($36) one coming from Dealextreme which I will review when I get them.








« Last Edit: February 19, 2013, 04:48:59 PM by PetrifiedWood »

Offline upthecreek

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Re: CST Berger pocket transit (compass)
« Reply #1 on: September 19, 2012, 07:10:47 PM »
Makes my brain hurt.....
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Offline PetrifiedWood

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Re: CST Berger pocket transit (compass)
« Reply #2 on: September 19, 2012, 07:30:55 PM »
Lol, looks complicated, but it's actually pretty easy to use.

These can be used to take a bearing one of 4 different ways, can be used as a signal mirror, can be used to find vertical angles, used as a level, and as a plumb bob. to use them with a TOPO map you will need a protractor so a baseplate compass is better to use with a map. And if you carry both you don't need a protractor and have a backup in case this one fails.

Offline Buckskin

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Re: CST Berger pocket transit (compass)
« Reply #3 on: September 19, 2012, 07:39:23 PM »
With that degree of graduations you ought to be on point every time, unless you of course you miss your declination percentage. 

Sweet looking tool.  Bet it cost a couple hand fulls of quarters.
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Online wolfy

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Re: CST Berger pocket transit (compass)
« Reply #4 on: September 19, 2012, 07:40:03 PM »
Pretty danged nice lookin' unit for the frogskins expended, PW :thumbsup:    Doesn't CST Berger make their own ball & socket mount that will fit the slots in the compass body?   You'll need the Brunton mount for the Brunton transit anyway, but I was just curious if one was available.  Do you own a non-ferrous tripod?  I was a little disappointed that the Brunton aluminum & brass tripod wasn't any taller than it is, but it is light and nice and solid........nice for packing around!

P.S......It makes my brain purr like a kitty :shrug:
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Offline PetrifiedWood

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Re: CST Berger pocket transit (compass)
« Reply #5 on: September 19, 2012, 09:17:05 PM »
I don't think Berger offers a ball mount but to be honest I never looked. I don't own a non-magnetic tripod. I do have a couple of the gorilla pods that are all plastic except for the mounting screw and had thought to machine a brass screw to replace the steel ones. I just cant bring myself to spend the $80 on the brunton tripod. I might have to keep a lookout on ebay. I have seen flat top surveying tripods for less and could make an adaptor plate for one of those to convert the 5/8-11 threads to 1/4-20 to fit the ball mount. I think those surveying tripods are non-magnetic anyway.

Offline OutdoorEnvy

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Re: CST Berger pocket transit (compass)
« Reply #6 on: September 20, 2012, 07:08:05 AM »
I think the major problem is that it says "Made in China"  :D   I mean who cares which end is painted what color and if it's level.  We made it with a total cost of 65 cents, including labor

It will be interesting to see the Brunton compared to this one though. 
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Offline MATT CHAOS

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Re: CST Berger pocket transit (compass)
« Reply #7 on: September 20, 2012, 08:00:16 AM »
I am interested in seeing the other compass you have incoming.  Keep us updated.
 ;)
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Offline Unknown

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Re: Review of CST Berger pocket transit (compass)
« Reply #8 on: February 19, 2016, 10:14:27 PM »
Hit reply and got that post-365 day warning again >:D
like it aint relevant today; of course it remains good; even if this was only meant for those following the TOKT news.  :popcorn: :[  sorry I have no clue what that was

   
What you are describing is exactly partially what I want to know how to do.

To paraphrase Wolfy wisely asking in his other review: How much doing are you gonna do?

 Good question! Good possibility that the answer is: not Much.

I surenuf do remain open to the possibility of discovering that I am just too damn dumb to approach unlocking the potential of even the worst knock-off... Nevertheless

What are the tests you might explain to your 10 year old(that's me, even if you think I'm only 2) to assure, at least, an acceptable modicum of accuracy of one's chosen instrument? 
   An "acceptable modicum" sounds silly. So what I mean by that is / What are some simple tests that show the dang thing is off.

The manufacturer gives us specs, how can we evaluate the accuracy? That's what I mean.
« Last Edit: February 19, 2016, 10:30:16 PM by Unknown »
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Offline PetrifiedWood

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Re: Review of CST Berger pocket transit (compass)
« Reply #9 on: February 20, 2016, 12:31:03 AM »
The first thing I would do, is place it on a flat level surface, and turn the entire thing until one end of the needle is at 0 degrees, and make sure the other end is at exactly 180 degrees. Do the same thing with 90 and 270 degrees. This ensures that the needle pivot point and the bezel with the graduations are concentric, and that the needle isn't bent. Adjust the declination 10 degrees or so in either direction and check concentricity again, just to be sure.

Make sure the point on the fold out sight lines up exactly with the lubber line scribed on the mirror. You can fold them both together above the compass dial and check alignment along the line by moving them in or out as needed.

Also check that the sight lines up with 0 degrees when folded down on top of the dial with declination set to 0.

With the entire thing opened up and lying flat, a thin piece of thread or a long hair can be stretched from one sight to another to make sure everything is aligned from the sights, to the lubber line, to the dial, to the needle.

To check actual accuracy, the simplest way is to place it level on a non magnetic support and take a bearing to a distant object, then compare to a bearing taken from the same position using a known good instrument.

Alternatively, you could find a road or highway or other feature with a known North/South orientation and sight along it, accounting for local magnetic declination.

The real Brunton pocket transits can be accurate to about a half degree, under ideal conditions with a good pair of reading glasses and a non magnetic tripod or other level support. But in a handheld application I would expect perhaps 2 to 4 degree practical accuracy from both the cheap ones and the real Bruntons.

If you want a great compass that packs easier and does probably 90% of what these do, have a look at my Silva Ranger review too.

http://bladesandbushlore.com/index.php?topic=4394.0
« Last Edit: February 20, 2016, 12:59:00 AM by PetrifiedWood »

Offline Unknown

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Re: Review of CST Berger pocket transit (compass)
« Reply #10 on: February 20, 2016, 03:24:37 AM »
1.Check 2.Check 3. Check 4. check 5. like a cell phone compass?
5a.  I guess I could plumb bob polaris. My 2' level was closest at hand to see how accurate I might be and it is undamaged, baring human error for bubble reading, its spec is .029 degrees. I can set up a test surface.

In the other thread i mentioned the Silva 27. It's miniature and I like it, cause my adventures are pretty small
I got no opposition to a full size Ranger or anything similar/better for a 90%er.  I wouldn't keep on if not to do a little bit more. I don't know. Like I said in Wlfs other thread, the pocket transit seems like something I should know. Maybe like pocket soup the effort will have little reward, but at least I'll know for sure.

In my trade of building things I've seen people make odd attempts at accuracy, like using a laser to set a door frame. I could set my level on it and show them they were off. They couldn't understand. :shrug: I liked using lasers too, very quick and simple to use when understood. It only takes a few attempts to discover that inaccuracies are cumulative. If you have the best level and read it sloppy, or a terrible level and see it true the result is similar. So I just developed a desire toKnow -is that right, is that accurate.

If there was a real need I'd have no problem with Brunton. I  don't. The least expensive model should serve beyond my needs as a novice discovering what it can do, sure. I just have a hard time being satisfied with the cheapest stuff. Getting the "best" is often a stretch to my budget and only a boost for my ego with a high probability that I'll ruin it before mastering it...

that's where "2 is one" comes from I think. you know, you don't quite get it so you opt for the cheapest. then you do, so you need a better one. the first becomes the back up-just in case.  :deadhorse: gettin' therehuh?
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Offline PetrifiedWood

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Re: Review of CST Berger pocket transit (compass)
« Reply #11 on: February 20, 2016, 09:13:11 AM »
Really, if you learn how to follow metes and bounds property descriptions you should be able to use one to traverse around an irregular shape lot pretty easily. The quadrant version makes that easier, but it also makes the compass less useful for all around stuff. I would rather have a baseplate compass for actual map and compass navigation. But for finding property corners without lugging around a big theodolite, these pocket transits can be handy.

I used this one to find some markers around the edges of my subdivision and a couple of my property corners.