[HamWAN PSDR] KU7M and his dBm

Fri May 23 20:17:09 PDT 2014

Is there anybody else connecting to the sector antennas that Dean and I are using?  (I know we are connecting to different sites, but to the two sector antennas in question?)

Sent from my iPad

> On May 23, 2014, at 7:19 PM, Bart Kus <me at bartk.us> wrote:
> 
> Sounds like we need to take a closer look at the vertical radiation pattern.  Maybe something is       actually going on there.
> 
> --Bart
> 
> 
>> On 5/23/2014 2:33 PM, Dean Gibson AE7Q wrote:
>> It may be "super weird", but I'm seeing the same thing.  My antenna is at 450';  the Paine antenna is at 750', and the distance between the two is almost exactly 26400'.  That's a rise of 300' in 26400', and the arc-sine of that ratio (0.0113636) is .65 degrees.  However, for optimum results, I have my antenna also aimed about 5 degrees above the horizon.  I don't remember the exact results when I aim at less than one degree, but it's significantly less.
>> 
>>> On 2014-05-22 13:28, Bart Kus wrote:
>>> That's super weird.  You might wanna try moving the mount up/down the mast while keeping the dish level.  And yes, microwaves can be mysterious until you get experience with them.  That's one big advantage of doing a project like this, it gives hams motivation to learn how to deal with 6GHz and such.
>>> 
>>> --Bart
>>> 
>>> 
>>>> On 5/22/2014 1:03 PM, Kenny Richards wrote:
>>>> Bart,
>>>> 
>>>> >Would you like some tower climbing / install help?  That's some crazy uptilt on the antenna picture you showed!
>>>> 
>>>>  Thank you for the offer, but I think it can wait until I'm healed. This was 'minor' knee surgery and I should be back to working out in six weeks, so I'm sure climbing the tower will be doable by then. We are at the very beginning of tower climbing season.... 
>>>> 
>>>> The crazy uptilt required was the source of most of my headaches. From that exact location, I will hear nothing with the antenna at the normal 'level' mount point. You need to tilt it up about five degrees or more before CP will register.  It never occurred to me that it would have that big of impact.  Microwaves are weird....
>>>> 
>>>> Thanks
>>>> Kenny
>>>> 
>>>> 
>>>> 
>>>>> On Wed, May 21, 2014 at 11:54 PM, Bart Kus <me at bartk.us> wrote:
>>>>> Dean,
>>>>> 
>>>>> I wouldn't limit your potential upside to 3dB with ... "spatial modulation".  :)  The vast majority of your path loss is NOT due to distance.  If you did achieve clear (or better) LoS, you could be looking at 30dB deltas.  Remember we've had Baldi-Tacoma (a far longer distance than yours) run at -57dBm during a signal survey.  K7JMM, across the Puget Sound (about 3x your distance) is running at -58dBm right now.
>>>>> 
>>>>> Kenny,
>>>>> 
>>>>> Would you like some tower climbing / install help?  That's some crazy uptilt on the antenna picture you showed!
>>>>> 
>>>>> --Bart
>>>>> 
>>>>> 
>>>>> 
>>>>> On 5/21/2014 9:27 PM, Kenny Richards wrote:
>>>>>> Dean,
>>>>>> 
>>>>>> I'm slightly less mad at you, but still a little peeved. :-)  
>>>>>> 
>>>>>> The shot to Capital Park from my house goes through quite a few tree's in my immediate area. (All within a couple blocks from me)  When I originally installed the tower about 10 years ago, I was able to see downtown from the top of it. Now I can't, due to the trees of the neighbor directly behind me and his neighbor.  
>>>>>> 
>>>>>> That said, I don't actually have the HamWAN antenna mounted on the tower yet. I had to postpone that installation until my knee heals up. (Had the meniscus repaired in my left knee last week)  Right now the antenna is mounted to a small mast at the apex of the roof. (It is sharing the mast with a VHF/UHF vertical)  
>>>>>> 
>>>>>> I thought that I'd posted links to these pictures before, but I guess not. 
>>>>>> 
>>>>>> Picture of current installation:  http://www.ku7m.net/drop/KU7M_HamWAN.JPG
>>>>>> 
>>>>>> Picture of what I'm shooting through to get to Capital Park: http://www.ku7m.net/drop/KU7M_CPView.JPG
>>>>>> 
>>>>>> And just because it makes me laugh, the installation from the first night it started working: http://www.ku7m.net/drop/DeckAntennaMount.jpg
>>>>>> 
>>>>>> The difference in signal strength from the antenna being on the deck railing to its current location is ~5 dB. The height difference between the to location is about eight to ten feet. When moving the antenna to the roof the first time, I had originally installed it on a mast located at the far east side of the roof. In this spot I could not hear CP at all. By moving the antenna to the mast located in the center of the house (which is about 20-25 feet west), the signal appeared and has so far been the best location.  I ordered another mast mounting kit for the eve located at the far west side of the house. When I'm feeling better I'll install it and see if the signal improves again when moving west. 
>>>>>> 
>>>>>> I don't have many data points on the impact of wind on the signal strength. I did check it on Sunday when a system blew through which was causing the trees to noticeable move. But I wasn't seeing much change in the signal strength. (maybe 1 db?)  
>>>>>> 
>>>>>> Thanks
>>>>>> Kenny
>>>>>> 
>>>>>> 
>>>>>> 
>>>>>>> On Wed, May 21, 2014 at 7:44 PM, Dean Gibson AE7Q <hamwan at ae7q.com> wrote:
>>>>>>> First of all, Kenny:  welcome!  Now that you have a HamWAN connection, I hope you are no longer mad at me.  Where is your antenna (inside/outside, height above ground, etc)?
>>>>>>> 
>>>>>>> On a related but more serious side, do you have a direct line-of-sight path to Capitol Hill, or do you go through trees?  The reason I ask is, my path goes through some trees.  When it is windy, that causes my RX signal level (dBm value) to vary about 5 dB (mostly down).  I have wondered whether mounting my antenna higher would help                                   my overall value (of course it would help when it is windy).
>>>>>>> 
>>>>>>> My average RX signal level is 80 dBm (no winds), and yours appears to be 83 dBm.  However, you are twice as far from your cell site as I am from mine, and since power falls off as the square of the distance, I'd expect (in similar configurations and siting) that you would experience a 6 dB difference.  Since the difference is only 3 dB, that suggests that (all things being equal, which they never are) I might gain at most 3 dB by moving the antenna.
>>>>>>> 
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>>>>>> 
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