Over Hill Test Results

[djrams80]

Here are the results from the testing Freebird and myself did last week. Let me know if you have any questions.

[chriskohtc]

What are the units to those numbers?

Miles from (Radar Gun/Crest of Hill?) before detection?

[djrams80]

What are the units to those numbers?

Miles from (Radar Gun/Crest of Hill?) before detection?

Oops, yep, miles from the radar gun. I'll edit it. Thanks. The radar guns were set up over the hill. The crest of the hill was at about 0.15 miles or so.

[MEM-TEK]

It looks like the 690SE being in operation at the same time as the 9500ci slaughtered the 9500ci's 35.5 Ka band range. I wonder whats up with that. My older Pro78 didn't have that kind of effect on my 9500ci. I notice that the V995 also somewhat hampered the 9500ci's Ka band range. Is that V995 an older S7 unit?

[djrams80]

It looks like the 690SE being in operation at the same time as the 9500ci slaughtered the 9500ci's 35.5 Ka band range. I wonder whats up with that. My older Pro78 didn't have that kind of effect on my 9500ci.

I'm just guessing, but there might be something wrong with my particular XTR-690SE. The interference was obvious. None of the other Whistlers did this, just that particular one.

I notice that the V995 also somewhat hampered the 9500ci's Ka band range. Is that V995 an older S7 unit?

It's an M4. The second run didn't show the same results, so it might have just been an anomoly. You know how these things go. Some results just can't be explained. The M4s all did surprisingly well, I'd say. Much better than I expected. We didn't test any S7s, because happya$$ didn't send them like he was supposed to.

Freebird and I were trying to think of reasons besides sensitivity, that might help some RDs see over hills better than others, but couldn't really come up with anything solid, besides horn shape and angle. Any guesses MEM-TEK,or any of you for that matter?

[stlcardsfan]

Looks like the 9500ix r@ped 35.5. Nice to see!

Why were the 2 Vectors models so different in performance on 35.5 GHz?

[KnightHawk]

Good test guys.

[djrams80]

Why were the 2 Vectors models so different in performance on 35.5 GHz?

They weren't, 0.460 mile average got the v955 and 0.473 mile average for the v995.

[MEM-TEK]

Freebird and I were trying to think of reasons besides sensitivity, that might help some RDs see over hills better than others, but couldn't really come up with anything solid, besides horn shape and angle. Any guesses MEM-TEK,or any of you for that matter?

It was either Jimbonzzz or Mike B who pointed out that over-the-hill performance depends a lot on a RD's ability to detect vertically polarized radar. With this in mind, I am just guessing that its primarily the vertically polarized component of radar from a radar gun which gets diffracted over the top of the hill.

In any event, radar scatter over a hill is extremely weak. Depending on exactly how well each radar gun is aimed each time for each test run could explain the slight range variances for each RD. You guys did a good job by conducting multiple runs for each RD in order to get a good average detection distance for each RD. It was also interesting to note how well the M4 antennas performed against 35.5 radar. I have been saying for quite some time that the M4 antennas have excellent on-axis sensitivity even though their off-axis sensitivity leaves something to be desired.

[djrams80]

Depending on exactly how well each radar gun is aimed each time for each test run could explain the slight range variances for each RD.

We mounted the radar guns in Freebird's truck, turned them on and never touched them again after that. We weren't aiming them.