Tropo of 26 March 2018

The general situation :

1-AIS RX

FRais-2018-04-26-12z.jpg	zs-station954-Durban-ais-2018-04-26-12z.jpg

fr5dn-best-ais distance	FR-AIS- almost 2200 kms in late evening

I lost some AIS at the best time. Best was 2715 kms at 0358z on 26/04/2018.

2-The Hepburn predictions

With my own maps to compare.

3-The troposphere profile

Not much data available at the right format to build profiles...

67197 FMSD Fort-Dauphin Observations at 00z 26 Apr 2018	67197 FMSD Fort-Dauphin Observations at 12z 26 Apr 2018

Here are the critical T° inversion forecast data (see ZS side 18z and 21z, increased altitude, that we noticed between ZS5LEE, ZS5DJ and myself).
In red are the highest value for inversion :

4-The surface pressure charts

They can be found here

5-The visible or IR maps - Eumetsat

7-The reports and some comments

I started the beacon on 25/04/2018 at 25w JT .
It started to be nicely heard in the morning of 26, with reports up to -3, -1, on zs side.
After work on thursday 26, i immediatly ran home, to start qsos!

1116z : ZS5DJ was 59 to 59+ SSB
1126z: ZS5DJ was 57 FM
1439z : ZS5HV was 55 FM
1445z: ZS5DJ 579 CW, i was only at 10w and heard at 529
1445z: ZS5HV 58 SSB

At same time i alerted the local hams to come and try, and here were FR8QP Alain, and FR5ZX Michel on the air.

FR8QP managed JT/SSB qso with ZS5HV, JT with ZS5LEE.
Good qso between FR8QP and ZS5HV on FT8 with +14db reports both sides.
FR8QP was with 10db yagi and 50w out.
In the JT qsos, FR5ZX Michel was rx only, with a small mobile vertical and could hear some JT from ZS.
Very interesting report with high altitude critical layer here.

Altitudes of stations : ZS5LEE 600m, ZS5DJ 50m, FR8QP 380m, FR5ZX 800m, and myself 300m.

After all that adrenalin, we qso a bit on the qrg on FR side, then off for dinner.

Then back on radio, and found ZS5LEE. Made some JT tests and SSB (53/52 1845z).
Power down to 10w at Lee side and still very nice signal here.
Then ZS5DJ (50m) was on the alert list and monitored the band. NIL from me, while i was good rx at Lee.
As Lee pointed, the altitude of the layers are generally better for him (600m) in late evening/night (see the above table of inversion).

8-Equipment at FR5DN :

On 2m:
In "beacon mode", 25-30w out into 17el F9FT-13dbd yagi at 7m above ground.
Old PC dedicated to the 2m station for digital modes and AIS receiver (modified FT-2500M).
For qso, i can use up to 120w out max in shack
Mast mounted LNA with BF981 feed through coax, no measurement on NF.
Coax is a low loss rigid coax LCF12-50, with some ecoflex 10.
I use separate TX and RX lines, which make things much more flexible, RX line is standard RG-213.
RX is Kenwood R-5000.
TRX for beacon and qso is dedicated Kenwood TR-9000.

On 70cms:

I run a now 4x21 el yagi at 2,5m above ground (lowest antennas)
Low loss coax, mixed length of hardline 7/8 and some length of lcf12-50 and LCF14-50.
Power 40w in-shack, higher if needed.
Mast mounted LNA 33db gain, 0.3db NF. Loss before LNA is around 0,9db.
RX is separated rx : LT70s converter with FT-990, 28Mhz IF.

The antennas used for the qsos:

Tks to All, and see you next opening !

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