OBSERVATIONS FROM HOLLAND.    March 2006        Aldert Kwak PH7PCF 

Not only satellites enthusiasts use sats for their communication. Sometimes, without even wishing it, I find myself in the middle of an NAC contest (Northern Activity Contest) or a European contest while I'm trying to listen to or work AO-7. This often has left me wondering exactly who it is who is using the wrong uplink frequency. If I switch to LSB on the downlink to see if it's a newcomer (like the newbie PH7PCF) inadvertently using AO-7's uplink frequency, I often find myself in the middle of a contest!.

A quick look at the different bandplans shows that not only the satellite enthusiast is “uplinking” in the 432.125 to 432.175 MHz (without Doppler)  region.  The bandplans here show that the 432.100- 432.399 region is being used for mixed-mode and weak-signal work. Each time there is some dx-activity taking place on UHF, European stations are using the uplink frequencies of AO-7.

(NB. It's important to note that after the changes made by the IARU, AO-7's uplink no longer falls within the designated satellite portion of the 70cm band ..... LA2QAA).

The 70cm loggings on march 5th 2006 showed the following active stations within the uplink freq of AO-7:

14:00  DF4IP      JN49HE   G4VHF/P  IO92QB     432.185  57  in JN49HE TROPO  

12:43  HA8AR   KN06MQ OK1KIK   JO70TQ     432.180  Tnx qso in kn06mq  TROPO  

12:43  DL1XAQ JO53FM   DL0RSH  JO43SV     432.162  CQ frm JO43SV 8*21ele 30 TROPO  
12:41  DF1JM    JO30EN    DF1JM     JO30EN     432.181  JO30FQ CQ TROPO  
12:27  DF1JM    JO30EN    DF1JM     JO30EN     432.180  CQ TROPO  
12:14  OE3LI     JN88EC    OE3A       JN77XX     432.150  jn77xx dir Stuttgart TROPO  
12:02  DB8WK  JO33XN   OE5D        JN68PC     432.183 TROPO  
12:01  PD0HCV JO31FW   G0VHF    JO01PU     432.187  5-9*** in jo31fw TROPO  
11:51  DF1JM    JO30EN    DF1JM     JO30EN     432.190  Looking for OK UNKNOWN
11:14  GM8IEM IO78MM  GM0USI   IO75UV    432.190  IO78<>IO75 TROPO  
11:05  M0BPQ   IO91WP   G0VHF/P  JO01PU     432.187 TROPO  
11:02  OE3LI     JN88EC    DH5UW    ??????       432.149  de oe3a ok to jo71ec!!!        UNKNOWN
10:58  DH5UW  ??????       OE3A       JN77XX     432.149  jn71ec  57 TROPO  
10:48  DF1JM    JO30EN    DF1JM     JO30EN     432.180  Looking for OK UNKNOWN
10:41  DF0MTL JO61JF     DL5YYM JO61HH     432.175  jo61jf call to jo31            TROPO  
10:33  OE3LI     JN88EC    DL6NCI    JO50VI      432.150  de oe3a jn77xx ur +db6nt qt    TROPO  
10:31  DF1JM    JO30EN    CQ/OK      ??????       432.180  JO30FQ TROPO  
10:09  DH6JR    JO31ID     OE5D        JN68PC     432.182  jo30-jn68 (dr5a) TROPO  
10:01  OE3LI     JN88EC    OE3A        JN77XX    432.150  jn77xx dir. yu Beograd lz +    TROPO  
09:21 DL8UWE JO61VR    9A1CAW  JN95GM    432.180  pse ant jo71dt UNKNOWN
09:20  DF1JM    JO30EN    CQ/OK       ??????       432.160  JO30FQ TROPO  
09:19  DK9TF    JO31NF    OE5D         JN68PC     432.183  pse ant jo31 UNKNOWN
09:15  9A2SB    JN95GM    9A1CAW   JN95GM   432.180  JN95GM qrv 70,23,13cm          TROPO  
09:13  DF1JM    JO30EN    CQ/OK        ??????      432.160 TROPO  

 

When I was working John LA2QAA and Terry G1WPR at 09.01 UTC that morning we had a lot of QRM on AO-7.

The QRM was at its highest level at 145.926 and around 145.940. Unfortunately the latter frequency  is precisely the one John usually uses, so having a decent QSO was almost impossible on AO-7 while in mode B that morning.

As most (read: "all") stations in a contest work with a far more power than the recommended few watts as used on sats, I could almost hear LA2QAA's pig’s heart going OINK OINK ... (LA2QAA has heart problems.....LA2QAA) .....with all the unnecessary QRM that these activities  produce on this fragile old lady of space, the effective remaining lifetime can be reduced dramatically, especially since AO-7 is a QRP only satellite,  running on solar power only.

 (John next time you’re in touch with Jan King, ask him for a possibility to move the uplink freq of AO-7 to the 435.000 – 438.000 region or ask the IARU to change the bandplans so that no interference is being caused by contest stations, in my opinion, it's rather like fighting windmills like Don Quichotte did some time ago.....PH7PCF).

 Should John, LA2QAA, however wish to do so, he could better move to Holland and enjoy the passes from this flat country from AOS till LOS.

One advantage of a higher uplink frequency would be that I would finally be able to make that sked with VU as they apparently are only allowed  to use 434.000 – 438.000.

To those active during the contests on UHF I would say, please remember the AO-7 passes and when the footprint is in your area, be so kind to QSY up, away from the uplink frequencies!

Aldert

PH7PCF