PowerFlARM at R5N Perry

On Monday, April 23, 2012 9:38:07 PM UTC-7, Kimmo Hytoenen wrote:
At 02:42 24 April 2012, Dave Nadler wrote:
On Monday, April 23, 2012 10:48:08 AM UTC-4, Dave Nadler
wrote:
I will post something later today, stand by...

Please see: http://powerflarm.us/2012/04/powerflarm-report-
from-perry/

See ya, Dave "YO electric"



It bis clear that any metal near the antenna disturbs
transmit/receive. How about the pilot? some sources say, that
human body is practically invisible for 868 MHz radio waves, some
people say that if you install antenna behind the front pilot in
double-seater, the transmission is blocked by pilots head.

Clear answer would be appreciated.

-kimmo

At these frequencies a human head is likely to have significant attenuation and putting a PowerFLARM or other similar devices (including PCAS receivers) in a two seater where its likely to be obstructed looking forward (where threat aircraft you might hit may be more likely to be..) is a bad idea. (You can Google for many documents on RF absorption of the human body). Another possible issue is metal components in front-seat headrests etc. And if the cockpit frame contains any metal parts (e.g. steel roll bars etc. -- I have no idea if common two seaters have steel roll bars in the canopy mid-frame) these may also be issues.

It seems a significant number of folks seem to be having problems mounting their PowerFLARMs properly hopefully this problem, can be reduced by revisions to the documentation. And the brick-version should make better antenna location easier for many owners--but I fear we'll still have a bunch of antennas installed below the glareshield buried amongst wiring, not vertically orientated, damaged/kinked coax, loose SMA connectors, etc ...


Darryl

On Apr 30, 4:51*pm, Darryl Ramm wrote:
On Monday, April 23, 2012 9:38:07 PM UTC-7, Kimmo Hytoenen wrote:
It bis clear that any metal near the antenna disturbs
transmit/receive. How about the pilot? some sources say, that
human body is practically invisible for 868 MHz radio waves, some
people say that if you install antenna behind the front pilot in
double-seater, the transmission is blocked by pilots head.

Clear answer would be appreciated.

-kimmo

At these frequencies a human head is likely to have significant attenuation and putting a PowerFLARM or other similar devices (including PCAS receivers) in a two seater where its likely to be obstructed looking forward (where threat aircraft you might hit may be more likely to be..) is a bad idea. (You can Google for many documents on RF absorption of the human body)........... (etc, its Daryl typing)..... etc...



Yes, but, (wait for it, drum-roll)...
Some heads are thicker than others.

On Monday, April 30, 2012 5:09:52 PM UTC-7, Dave Nadler wrote:
On Apr 30, 4:51*pm, Darryl Ramm wrote:
On Monday, April 23, 2012 9:38:07 PM UTC-7, Kimmo Hytoenen wrote:
It bis clear that any metal near the antenna disturbs
transmit/receive. How about the pilot? some sources say, that
human body is practically invisible for 868 MHz radio waves, some
people say that if you install antenna behind the front pilot in
double-seater, the transmission is blocked by pilots head.

Clear answer would be appreciated.

-kimmo

At these frequencies a human head is likely to have significant attenuation and putting a PowerFLARM or other similar devices (including PCAS receivers) in a two seater where its likely to be obstructed looking forward (where threat aircraft you might hit may be more likely to be..) is a bad idea. (You can Google for many documents on RF absorption of the human body)........... (etc, its Daryl typing)..... etc...



Yes, but, (wait for it, drum-roll)...
Some heads are thicker than others.

Ugh your excused (it's Dave typing).

Darryl

Not thicker, just less permeable...
Idea attenuation is higher in these heads.

Conversely, and logically, certain heads have very low density and
nearly zero attenuation. Ideas pass unimpeded through these.



On 2012/05/01 2:09 AM, Dave Nadler wrote:
On Apr 30, 4:51 pm, Darryl wrote:
On Monday, April 23, 2012 9:38:07 PM UTC-7, Kimmo Hytoenen wrote:
It bis clear that any metal near the antenna disturbs
transmit/receive. How about the pilot? some sources say, that
human body is practically invisible for 868 MHz radio waves, some
people say that if you install antenna behind the front pilot in
double-seater, the transmission is blocked by pilots head.

Clear answer would be appreciated.

-kimmo

At these frequencies a human head is likely to have significant attenuation and putting a PowerFLARM or other similar devices (including PCAS receivers) in a two seater where its likely to be obstructed looking forward (where threat aircraft you might hit may be more likely to be..) is a bad idea. (You can Google for many documents on RF absorption of the human body).......... (etc, its Daryl typing)..... etc...



Yes, but, (wait for it, drum-roll)...
Some heads are thicker than others.

--
Bruce Greeff
T59D #1771