Rich in NEPA

The term "memory effect" refers to a specific situation that occured in certain (very early) satellite applications, which used a NiCad cell made with sintered plates. No commercial consumer-grade NiCad cells have ever been made with this process. So, all you are doing is "redefining" the term, which is a simple trick of semantics ... like calling a dog a cat. "Voltage depression" (which is NOT "memory") is something that can occur with any of the current rechargeable battery technologies. If you read the article I quoted (or dozens of other "independant" test results), you'll see that voltage depression is indeed a real issue and a problem. Memory effect is NOT. Let's face it ... NiMH and Li-Ion battery manufacturers like to play on consumer ignorance (and dread!) of NiCad memory when they claim that THEIR products have no "memory." Of course that's true, because they know that memory doesn't exist, and are cleverly implying that it does in competing products. Their own advertising counts on the fact that, as everyone knows!!!, NiCads have memory. See what I mean about gullibility? [Edit] Ooops! ... I forgot there was something else I wanted to mention. When someone is aware of a misconception of this kind, isn't it advisable to make an effort to correct it rather than encouraging it? Cheers ... ~Rich in NEPA~ === A man with a GPS receiver knows where he is; a man with two GPS receivers is never sure. === [This message was edited by Rich in NEPA on March 31, 2002 at 06:43 PM.]

There's no such thing as NiCad battery Memory Effect. ~Rich in NEPA~ === For every credibility gap, there is a gullibility fill. === [This message was edited by Rich in NEPA on March 31, 2002 at 12:59 PM.]

quote:Originally posted by niskibum: ... everyone knows that the aluminum must be in the shape of a pyramid to be effective! That's only if you want to keep your mind sharp. ~Rich in NEPA~ === The dumber people think you are, the more surprised they're going to be when you kill them. ===

quote:Originally posted by niskibum: ... everyone knows that the aluminum must be in the shape of a pyramid to be effective! That's only if you want to keep your mind sharp. ~Rich in NEPA~ === The dumber people think you are, the more surprised they're going to be when you kill them. ===

So far I'd have to vote for New York/New Jersey Multi-State Multi-Cache placed by Waterboy with Wife (WWW). Very challenging hike providing terrific scenery and views. Lookout Lake is a very pleasant hike with a pretty lake and a surprising challenge. I think New Jersey has some fine recreation areas. Cheers ... ~Rich in NEPA~ === A man with a GPS receiver knows where he is; a man with two GPS receivers is never sure. ===

quote:Originally posted by vertigo235:The answer apears to be Vertical, not on it's side. Why is it that some people have to read things into a post that isn't there?! Geez ... Vertigo, we know that you're supposed to hold it upright and not on it's side. Please read the posts more carefully. Thank you. (I'm only teasing you.) However, the question is in regards to the physical orientation of the antenna inside the unit. A quadrifilar antenna is cylindrical in shape, about the size of a AA battery. It appears the only way that Garmin could stuff one into the map76's case is to lay it on its side, parallel to the two batteries, and within the bulging section under the logo. Since quadrifilar antennas are designed to operate in a vertical orientation (like a smokestack), the question becomes how does the Garmin configuration affect the performance of such an antenna? BTW, EraSeek, the reply you got from Garmin doesn't surprise me. It's as if they didn't even bother to read your message! Thanks for trying. Cheers ... ~Rich in NEPA~ === A man with a GPS receiver knows where he is; a man with two GPS receivers is never sure. ===

quote:Originally posted by vertigo235:The answer apears to be Vertical, not on it's side. Why is it that some people have to read things into a post that isn't there?! Geez ... Vertigo, we know that you're supposed to hold it upright and not on it's side. Please read the posts more carefully. Thank you. (I'm only teasing you.) However, the question is in regards to the physical orientation of the antenna inside the unit. A quadrifilar antenna is cylindrical in shape, about the size of a AA battery. It appears the only way that Garmin could stuff one into the map76's case is to lay it on its side, parallel to the two batteries, and within the bulging section under the logo. Since quadrifilar antennas are designed to operate in a vertical orientation (like a smokestack), the question becomes how does the Garmin configuration affect the performance of such an antenna? BTW, EraSeek, the reply you got from Garmin doesn't surprise me. It's as if they didn't even bother to read your message! Thanks for trying. Cheers ... ~Rich in NEPA~ === A man with a GPS receiver knows where he is; a man with two GPS receivers is never sure. ===

quote:Originally posted by Myra Mit:It's amazing that the same kind of rookie GPS mistake that may cause me to walk an extra couple miles can also get a whole lot of people killed ... Wow, that would spoil your day! ~Rich in NEPA~ === A man with a GPS receiver knows where he is; a man with two GPS receivers is never sure. ===

quote:Originally posted by Myra Mit:It's amazing that the same kind of rookie GPS mistake that may cause me to walk an extra couple miles can also get a whole lot of people killed ... Wow, that would spoil your day! ~Rich in NEPA~ === A man with a GPS receiver knows where he is; a man with two GPS receivers is never sure. ===

quote:Originally posted by Rob H.:Nope, this thing. It's called the Segway and it's truly a marvel of modern engineering! Even the USPS is looking into supplying them to letter carriers. Cheers ... ~Rich in NEPA~ === A man with a GPS receiver knows where he is; a man with two GPS receivers is never sure. ===

quote:Originally posted by Rob H.:Nope, this thing. It's called the Segway and it's truly a marvel of modern engineering! Even the USPS is looking into supplying them to letter carriers. Cheers ... ~Rich in NEPA~ === A man with a GPS receiver knows where he is; a man with two GPS receivers is never sure. ===

quote:Originally posted by Growley:Hope this adds to the overall confusion! Growley, thanks for the effort you put into this. From your results it seems safe to suggest that the GPSmap76's antenna is indeed very directional. I've been searching the Web for similar discussions and haven't found anything to add to what we already know. For example, from Autonomous GPS Accuracy Report comes the following: quote: For example the Garmin 12XL manual shows the suggested orientation of the receiver which is about 25 degrees up from horizontal. The GPSMAP76 manual only suggests that the top of the unit be tilted upward. While in the open the GPSMAP76 works well with the unit tilted up about 40 degrees from horizontal, it performs terribly under canopy like this. The antenna is highly directional, which can be seen by watching the satellite signal strength bars while rotating the receiver, and the above results were obtained by holding the receiver vertically. Interestingly enough, the 12XL performed the same either horizontally (actually up about 25 degrees) or vertically under the above conditions. Cheers ... ~Rich in NEPA~ === A man with a GPS receiver knows where he is; a man with two GPS receivers is never sure. ===

quote:Originally posted by Growley:Hope this adds to the overall confusion! Growley, thanks for the effort you put into this. From your results it seems safe to suggest that the GPSmap76's antenna is indeed very directional. I've been searching the Web for similar discussions and haven't found anything to add to what we already know. For example, from Autonomous GPS Accuracy Report comes the following: quote: For example the Garmin 12XL manual shows the suggested orientation of the receiver which is about 25 degrees up from horizontal. The GPSMAP76 manual only suggests that the top of the unit be tilted upward. While in the open the GPSMAP76 works well with the unit tilted up about 40 degrees from horizontal, it performs terribly under canopy like this. The antenna is highly directional, which can be seen by watching the satellite signal strength bars while rotating the receiver, and the above results were obtained by holding the receiver vertically. Interestingly enough, the 12XL performed the same either horizontally (actually up about 25 degrees) or vertically under the above conditions. Cheers ... ~Rich in NEPA~ === A man with a GPS receiver knows where he is; a man with two GPS receivers is never sure. ===

quote:Originally posted by Moun10Bike: I know what we need, Rich -- you should crack your unit open and confirm the antenna orientation for the rest of us! M10B, I think I'll pass on that experiment for now. But, it would be interesting to know what it looks like inside. I'm sure somebody out there has attempted to hack this unit. quote:I think I am visualizing what you are suggesting -- that the linear antenna runs left to right under the logo, so that when you flip the unit on its side, it is vertical? Yes!!! That's exactly what I'm attempting to explain. I should have drawn a diagram and avoided most of the confusion. I can see that Garmin wanted to make the case design more elegant than the Magellan units which have that odd protrusion on the top where they put their quad-helix antenna. But, how does Garmin's decision affect the performance of that type of antenna? ~Rich in NEPA~ === A man with a GPS receiver knows where he is; a man with two GPS receivers is never sure. ===

quote:Originally posted by Moun10Bike: I know what we need, Rich -- you should crack your unit open and confirm the antenna orientation for the rest of us! M10B, I think I'll pass on that experiment for now. But, it would be interesting to know what it looks like inside. I'm sure somebody out there has attempted to hack this unit. quote:I think I am visualizing what you are suggesting -- that the linear antenna runs left to right under the logo, so that when you flip the unit on its side, it is vertical? Yes!!! That's exactly what I'm attempting to explain. I should have drawn a diagram and avoided most of the confusion. I can see that Garmin wanted to make the case design more elegant than the Magellan units which have that odd protrusion on the top where they put their quad-helix antenna. But, how does Garmin's decision affect the performance of that type of antenna? ~Rich in NEPA~ === A man with a GPS receiver knows where he is; a man with two GPS receivers is never sure. ===

quote:Originally posted by Hawk-eye: Well so far this morning ... no "White Screens of Death" .. Hawk-eye, the gremlins must have moved on to better pickins 'cuz I've been plagued with them all morning. Just about every other time I click to a thread I get the white screen of death!!! It's definitely annoying. Guess it's going to be a while before the bugs are finally worked out of the new forums. ~Rich in NEPA~ === A man with a GPS receiver knows where he is; a man with two GPS receivers is never sure. ===

quote:Originally posted by Hawk-eye: Well so far this morning ... no "White Screens of Death" .. Hawk-eye, the gremlins must have moved on to better pickins 'cuz I've been plagued with them all morning. Just about every other time I click to a thread I get the white screen of death!!! It's definitely annoying. Guess it's going to be a while before the bugs are finally worked out of the new forums. ~Rich in NEPA~ === A man with a GPS receiver knows where he is; a man with two GPS receivers is never sure. ===

T-J, that's such a bummer! I know the feeling since I had a vehicle broken in to twice (same vehicle), ... once in the parking lot where I worked, and once at a restaurant. Parks (including Nat'l Parks) and remote recreation areas have been prime locations for vehicle beak-ins for a long time because these dirtbags know the owners will be away from their cars for enough time for them to strike and get away unnoticed. Funny thing is, around here you don't hear about break-ins during the hunting seasons!!! ~Rich in NEPA~ === A man with a GPS receiver knows where he is; a man with two GPS receivers is never sure. ===

T-J, that's such a bummer! I know the feeling since I had a vehicle broken in to twice (same vehicle), ... once in the parking lot where I worked, and once at a restaurant. Parks (including Nat'l Parks) and remote recreation areas have been prime locations for vehicle beak-ins for a long time because these dirtbags know the owners will be away from their cars for enough time for them to strike and get away unnoticed. Funny thing is, around here you don't hear about break-ins during the hunting seasons!!! ~Rich in NEPA~ === A man with a GPS receiver knows where he is; a man with two GPS receivers is never sure. ===

quote:Originally posted by Moun10Bike:I took your comment to Geoffrey stating that you "seriously doubt that this is the situation with the GPSmap76" when he mentioned that the GPSMap "has to be as close to vertical as possible" to mean that you disagreed with the evidence that the unit has to be held this way for best reception. I was afraid that my point was getting lost in the "translation." What I'm getting at may sound strange, but the only way I believe you can get the antenna itself in the 76/map76 in the vertical position is to flip the unit on its side (so that the logo is to the right or to the left, but still facing you). I have to admit what surprises me most is that the issue of the 76/map76's unusual antenna design hasn't been a "hot topic" on this forum. I think some of the problem with reception when the unit is held flat (as would be preferred with a patch antenna) is that the components inside the case would obscure a portion of the pattern. With the unit held vertically, these components are beneath the antenna toward the ground. I've noticed very little change in signal strength when shifted from vertical to flat so long as the unit is held further away from me. I still need to experiment with turning the unit on its side (logo to right or left, facing me) so that that antenna is truly vertical (but I still wouldn't be sure which side the "top" of the antenna is at!) I certainly wouldn't want to use the unit in this manner, but I'm curious if this has much of an effect. What do you think? Thanks for the link to the latest Manual. I'll be downloading the file for printing momentarily. Cheers ... ~Rich in NEPA~ === A man with a GPS receiver knows where he is; a man with two GPS receivers is never sure. === [This message was edited by Rich in NEPA on March 26, 2002 at 10:44 AM.]

quote:Originally posted by Moun10Bike:I took your comment to Geoffrey stating that you "seriously doubt that this is the situation with the GPSmap76" when he mentioned that the GPSMap "has to be as close to vertical as possible" to mean that you disagreed with the evidence that the unit has to be held this way for best reception. I was afraid that my point was getting lost in the "translation." What I'm getting at may sound strange, but the only way I believe you can get the antenna itself in the 76/map76 in the vertical position is to flip the unit on its side (so that the logo is to the right or to the left, but still facing you). I have to admit what surprises me most is that the issue of the 76/map76's unusual antenna design hasn't been a "hot topic" on this forum. I think some of the problem with reception when the unit is held flat (as would be preferred with a patch antenna) is that the components inside the case would obscure a portion of the pattern. With the unit held vertically, these components are beneath the antenna toward the ground. I've noticed very little change in signal strength when shifted from vertical to flat so long as the unit is held further away from me. I still need to experiment with turning the unit on its side (logo to right or left, facing me) so that that antenna is truly vertical (but I still wouldn't be sure which side the "top" of the antenna is at!) I certainly wouldn't want to use the unit in this manner, but I'm curious if this has much of an effect. What do you think? Thanks for the link to the latest Manual. I'll be downloading the file for printing momentarily. Cheers ... ~Rich in NEPA~ === A man with a GPS receiver knows where he is; a man with two GPS receivers is never sure. === [This message was edited by Rich in NEPA on March 26, 2002 at 10:44 AM.]

quote:Originally posted by Moun10Bike:Rich, if you take a look at page 21 in the manual and observe the graphic, I think that you'll agree that Geoffrey is right. Mount10bike, I think we are having some difficulty getting on the same wavelength. I'm not questioning the issue of holding the unit in a vertical position (logo upward). What I'm trying to explain is that the antenna itself, physically, is NOT oriented to the vertical in side the case. I realize that units with patch antennas should be held mostly with the logo facing upward, since the reception bias is perpendicular to the surface of the antenna. The reception bias of a quad-helix antenna is in a plane perpendicular to its axis. What I believe this means in the case of the 76/map76 receivers, is that the bias is not toward the horizon as would be the case with the III+/V, but in a plane that is 90° to the horizon (assuming you are holding the unit as recommended). Am I explaining this clearly? It's kinda frustrating. (As an aside, I think we even have different User Manuals. My page 21 doesn't have a graphic showing how the unit should be oriented, only a screen shot of the Satellite Status display. The instructions are: "Turn the unit on and hold it in front of you with the top of the unit tilted upward." That's it. No other mention of how to hold the unit. Perhaps there is a newer version.) Cheers .... ~Rich in NEPA~ === A man with a GPS receiver knows where he is; a man with two GPS receivers is never sure. ===

quote:Originally posted by Moun10Bike:Rich, if you take a look at page 21 in the manual and observe the graphic, I think that you'll agree that Geoffrey is right. Mount10bike, I think we are having some difficulty getting on the same wavelength. I'm not questioning the issue of holding the unit in a vertical position (logo upward). What I'm trying to explain is that the antenna itself, physically, is NOT oriented to the vertical in side the case. I realize that units with patch antennas should be held mostly with the logo facing upward, since the reception bias is perpendicular to the surface of the antenna. The reception bias of a quad-helix antenna is in a plane perpendicular to its axis. What I believe this means in the case of the 76/map76 receivers, is that the bias is not toward the horizon as would be the case with the III+/V, but in a plane that is 90° to the horizon (assuming you are holding the unit as recommended). Am I explaining this clearly? It's kinda frustrating. (As an aside, I think we even have different User Manuals. My page 21 doesn't have a graphic showing how the unit should be oriented, only a screen shot of the Satellite Status display. The instructions are: "Turn the unit on and hold it in front of you with the top of the unit tilted upward." That's it. No other mention of how to hold the unit. Perhaps there is a newer version.) Cheers .... ~Rich in NEPA~ === A man with a GPS receiver knows where he is; a man with two GPS receivers is never sure. ===

quote:Originally posted by Geoffrey:If you stood it up vertically, it's Antenna would be vertical, behind the Garmin Logo. Geoffrey, this is where I think you are wrong, and I'm not just trying to be argumentative. Look at the shape of the case just above the battery compartment (under the logo). The quadriliar antenna has the shape of an elongated cylinder. (Hence the shape of the movable antennas on the III+ and V, for example.) There is no way it can be aligned vertically in the map76. It has to be turned 90° on its side. Imagine a AA-size battery behind the logo that is parallel to the unit's own batteries. The quad-helix (or guadrifilar) design was chosen as a compromise for better gain at the horizon. (Pic indicates typical radiation pattern.) Now turn this diagram on its side. Can you see what I'm getting at? How does this configuration compare with the reception characteristics of both the typical patch antenna and the "vertically oriented" GPS-III+ and GPS-V antennas? I guess this is what I'm most curious about. Cheers ... ~Rich in NEPA~ === A man with a GPS receiver knows where he is; a man with two GPS receivers is never sure. ===

Moun10Bike, what sort of experiences have you had with your map76? How does it compare with other units you may have had, or have now? Where I am, I can receive the WAAS signal about 60% of the time but find that I get slightly different position fixes compared to the older 12XL. With WAAS disabled, the two units match nearly perfectly. I really like the map76's display and its configurability. The unit is a pleasure to use in the field. I'm just having a hard time learning to live with some of the signal reception quirks. Cheers ... ~Rich in NEPA~ === A man with a GPS receiver knows where he is; a man with two GPS receivers is never sure. ===