[MVMA] New local AREDNite: Steve KD8MKG

[Chuck Gelm]

On 6/29/23 17:14, kd8mkg wrote:
> Hey Chuck,
>
> /Sending a second message because the listserv didn't like my large 
> image attachment./
>
> Understood.  I found the documentation last night and have been 
> reading/watching through it and I am developing a better understanding 
> of the topology and equipment.
>
> And that's quite a generous offer!  It's much appreciated, but 
> generally, I prefer to own and operate my own equipment.  
> Additionally, cost is not a factor for me, so I'd much prefer that 
> loaner equipment go to potential new users who may have fewer 
> resources, or be available for backup purposes.  That being said, I'm 
> not in a huge hurry or anything, I just enjoy learning and 
> experimenting.  I suspect this isn't a unique quality among this group.
>
> In performing a 5.7GHz link analysis based on your parameters (60˚ 
> coverage, assuming a conservative 10dBi gain from Prestige at the 
> slight offset), with an LGH 5 XL mounted to the mast at my QTH, the 
> numbers appear a bit more comfortable, though still in a range I would 
> consider marginal.  The receive performance specifications for the LHG 
> 5 XL are right around where I was estimating, and it looks like I'd be 
> into the green with a small fade margin of ~12dB.  Of course, that 
> rmonline isn't estimating a "forest loss" makes me wonder how accurate 
> it might be in this case.  I trust it implicitly for UHF and below.  
> It's relatively reliable for 915MHz, but for 2.4GHz and up, I'm not sure.
>
> -Steve
>
> On Thu, Jun 29, 2023 at 7:09 AM Chuck Gelm <nc8q-aredn at gelm.net> wrote:
>
>     On 6/28/23 12:48, kd8mkg wrote:
>>     Hey Chuck,
>>
>>     Thanks for this!  Do you have a ballpark idea of the receive
>>     threshold performance for these radios?
>>
>>     Online I'm reading indications that ~80dBm is the absolute floor
>>     of something that's marginally reliable; but this source seems to
>>     indicate it is referring to consumer devices.  Assuming antennas
>>     with a gain of 12dBi at both ends, and 500mW Tx power, my link
>>     study suggests a total path loss of ~140dB, and receive at about
>>     -94dBm.  Rokland sells a 2.4GHz panel with a claimed 19dBi gain
>>     and a 17˚ beam width, which would hypothetically get me to around
>>     -86dBm.  If I paid for dedicated hardware at both ends, and had a
>>     19dBi panel at prestige, I could get myself into the yellow at
>>     about ~79.86dBm.  It is possible, though, that these commercial
>>     radios are more sensitive than I'm assuming.
>>
>>     I have field experience with the 915MHz LoRa hardware, but I'm
>>     sort of guessing with this stuff. And perhaps more importantly,
>>     as my brother says; /in theory, practice matches theory; in
>>     practice, it does not. /Considering the low cost of entry, the
>>     best course of action might just be to put up an antenna and see
>>     what happens.
>>
>>     Cheers!
>>     Steve
>>
>>     On Wed, Jun 28, 2023 at 5:38 AM Chuck Gelm <nc8q-aredn at gelm.net>
>>     wrote:
>>
>>         On 6/28/23 04:39, Chuck Gelm wrote:
>>>         Here is Steve's profile toward Prestige Plaza:
>>
>     Hi, Steve:
>
>     Your theory looks fine, but don't buy anything, yet.
>     1. We have equipment to loan.
>     2. Since 2018 we have been discouraging grid access via 2.4 GHz.
>     3. Rokland does not make devices compatible with AREDN firmware.
>     See: http://downloads.arednmesh.org/firmware/html/SUPPORTED_DEVICES.md
>     Note that most of the compatible devices are packaged with a radio
>     and its antenna in one enclosure.
>     There may be one radio used with 3 different antenna. Mikrotik RB
>     SXTsq, LHG, LHG-XL.
>     I have a 'panel' (SXT 16dBi) and 2 'dish' (24.5, 27 dBi)
>     radio/antenna devices to loan.
>     There already is a 60 degree beamwidth device at PP and it is
>     aimed about 285 degrees. You are about 8 degrees.
>
>     73, Chuck
>
>
Test the loaner equipment.
If it works, buy your own.
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