PAmicrowaves
Maart 29, 2024, 09:39:49 *
Welkom, Gast. Alsjeblieft inloggen of registreren.

Login met gebruikersnaam, wachtwoord en sessielengte
Nieuws: SMF - Just Installed!
 
   Startpagina   Help Zoek Kalender Inloggen Registreren  
Pagina's: [1]   Omlaag
  Print  
Auteur Topic: New UK 76GHz distance record today 14th September 2013  (gelezen 3533 keer)
Eene de Weerd PA3CEG
Administrator
Full Member
*****
Berichten: 197



« Gepost op: September 14, 2013, 09:19:19 »

Today 14th Setember a new distance record was made (until challenged) on 76GHz from G to GW
IO80RT59 Batcombe Hill,Dorset to IO81IO36 Eglwysilan,Gwent 102Km. Operating on three band, 24, 47 and 76GHz were G8BKE/P and G8ACE/P at Batcombe and also on the three bands at Eglwysilan were GW8KQW/P and with valuable assistance from GW3TKH. All three bands were worked using FM with full duplex FM operation on 76GHz between G8KQW and G8ACE with one way FM between G8BKE and G8KQW. Signals on 76G were exchanged for over two hours with a very gradual increase in average signal strength with some qsb initially. Both Tx and Rx were locked using RDDS PLLs at G8ACE and the G8KQW Tx RDDS locked.
This was the first time locking was used at both ends and meant the 76GHz signal was acquired within seconds due to the accurate frequency control. References used for the PLLs were 10MHz double ovened OCXO. Some video evidence will be posted when G8ACE has had time to upload it.
It has been very difficult to improve on the previous record distances primarily due to the earth being curved. So far if the path is not optical then it doesn't work, none of this K=1.33 stuff on 76G with the tiny power levels used.
We are indepted to Keith GW3TKH for the suggestion of this path which is LOS and for his assistance in guiding Ian G8KQW up the Welsh mountain.
I will announce when some pictures and video are available.
73s John G8ACE
Gelogd
Eene de Weerd PA3CEG
Administrator
Full Member
*****
Berichten: 197



« Antwoord #1 Gepost op: September 27, 2013, 01:50:49 »

A video of the 76GHz 102 Km distance record announced here about ten days ago is now available for viewing.  Two site URLs below. First one is possibly the better quality.  Second one, a web page seems to limit daily connection usage. 
https://docs.google.com/file/d/0B9s-pRG6smmGbTF2VkMxcmtjaFk/edit?usp=sharing
 
www.microwaves.zxq.net/76GHz/76GHz.html
 
 
There is quite a lot of wind noise to the audio at times.  All of the cameras suffered this with the internal mics.  Also I managed to leave my 47G Rx hissing at one time.
Its a fairly long video at 19 minutes duration but hopefully will convey the good time we were having pushing the boundaries on 76GHz.
73s John G8ACE
Gelogd
Pagina's: [1]   Omhoog
  Print  
 
Ga naar:  

Powered by MySQL Powered by PHP Powered by SMF 1.1.10 | SMF © 2006-2009, Simple Machines LLC Valid XHTML 1.0! Valid CSS!