Posts

Showing posts from July, 2017

50MHz Sunday 30 July

Image
2017  is the  breakthrough  of 50MHz JT65 FT8  causing  a huge 50MHz activity boost  this could happen on 4m 2m and UHF too 

50.276 MHz   in the Morning open to Japan  09:07  -- 10:49
just after I went in the garden since band was very very  quiet...
 rx left on  in JT65 mode   50.276:
    JF3MYA JA3EGE JH3VJV JQ3DUE JH0RNN JH4UYB JA7QVI JA8QNF
JM1SZY JE1BMJ JM1KNQ
evening short open to USA   fast mode FT8
12:17 K1TOL               latest   signal 12:43
WU1ITU     K7BV FM04   N1BUG

Guess next LOTW update allows mode FT8 QSO records upload.
The fast 15 seconds digi mode is an alternative to the 2 minutes slow cycle of JT65
Found that this FT8 mode is working great with VHF UHF fluttery tropo signals
FT8 need stronger signals to decode but it can use short strong openings.

 Although it is hard to find UHF HAMS  using digimodes at f.i. 23cm
most VHF / UHF  hams seem to use hand keys and paper logs ??


TQSL  accepts 51 modes but the latest FT8 is missing
In LOTW  mode  FT8 and others can…

1296.500 MHz JT65 and FT8 test

Image
Today  digimode  JT65 and FT8   was tested at 23cm for first time here
with Ole OZ2OE and Thorben OZ3ZW

Signals strong but fast  QSB and Airplane scatter on top.
FT8 seems to handle the fluttery signals best
almost 100%  decoding in FT8 mode  while JT65 had some not decoded frames.

                                                     JT65

RF_AMP 45W EBAY

Image
Very well designed, high quality PCB all parts neatly packed. With the correct diagram relative easy to build. The newest PCB is June 2016 documentation pictures shown at Ebay are outdated  incredible  value for money 14$ Although could not yet test with RF  due too high bias Q2 0.6A - 0.7A even with shorted B-E  0.6A flowing Considering the very low prize  the supplied 2SC1971 might be a fake Mitsubishi does not longer produce this or replacements TO220 medium power RF transistors?  If someone could give a hint which eBay  2SC1971 good quality original Misubishi  is a real working one That would be much appreciated 
left is the supplied "2SC1971" not working 0.6A and not adjustable bias right is a better working possible original Misubishi it is 1mm smaller  DutchRFshop With that one i could adjust the bias to 100mA   ( diagram below  R5=330 OHm)  
 the bias of the IRF530 need to be about 25 50mA  no more no less for max gain it is a bit tricky adjusting the 2 potmeters the…

JT65

Image
several JA decoded this morning in JT65    signals too weak for FT8


WSJT-X V1.8 first tests

Sunday AURORA 70MHz  recording GM4ZUK/P
http://www.qsl.net/pa0oos/2017/GM4ZUK_4MAU.mp3

Installed the latest WSJT-X V.1.8.rc1 beta version

on a W7 32b DELL D420 notebook

It crashed few seconds  after start  several times  need to force stop with p.m.

After rebooting PC it was ok with CAT to the K3

In between i started V1.6 again
Frequency settings of  V1.6  where lost and needed reset to default.
these setting are removed by V1.8  and vice versa.

Then i had the first FT8 mode contacts  LX1JX groundwave dial 50.313
only ground wave with some MS enhanced scatter are possible in the present propagation dip.

The frequency dial settings are depending to the selected  region  ,  1 2 3 or all
They are different to   version 1.6        WSPR 50.293  JT65 50.276
Set to Region1  was  USB 50.310 as default JT65 not 276
in the band selection list box there are 3 6m entries when  regions "all"  is selected
the first is the usual 50.276
80m WSPR no spots freq. must be modified 3.592600  it …

IC706 classic repair

Image
IC706 classic  was damaged by high RF at 144 input I use this old but very good rig as 146-148  i.f for 1296MHz  XVTR Receiving Graves at 143.050  pings and scatter i forgot to disconnect the VHF antenna   ( 3 band 6,4,2) when transmitting at 6m with the 7 el just underneath so it became very quiet at 23 / 144.. 144-148 /VHF input circuit part with 3-PIN antenna switch  and MA862 band switch that switches between 2 input filters. TOP = 60-200 MHz  down is 144-148 bandpass preselection in front of the    uPC1658G  wide band preamp


MA862  bandswitch fried by high 50MHz signal at 144 /VHF input SO239

replaced by 2 BA891 bandswitch diodes Ebay 


above temporary jumper to select 144-148 band pass filter without the bandswitch diodes the IC706 does not switch to the VHF filter when tuning outside the 144-148 range  a solution without bandswitch But the burned out  MA862 protected the IC706 preamp against further serious damage So it is better to have  bandswitch diodes placed there 4 pole t…

50MHz wijd open typisch ná het weekeind

Image
very good 6m opening Monday 3 Juli 2017

many DX heard sorry not all heard DX resulted in 2-way because of  JT65 slow QSO rate
Briefly  check of CW part but no promising sounding signals.

wsjt log to search your decode

( 6m)  dx rules:
1 best DX is not during weekend's
2 good openings never repeat next day

Als vanouds ná weekend  op maandag ochtend 6M band  open  voor DX Japan Korea China
in het weekend was het dacht ik niet veel soeps.

Antenne moet toch wel echt op QTF 030 voor JA
Korea 3 stations  veel JA   China 2 stations , de 1e keer dat ik hier zelf China op het scherm zie.
Nu lukte het met BA4SI   al vaak super zacht in CW gehoord  nu met JT65  wel.

Heel vroeg open 07 UTC al eerder deze week heel vroeg rond 05 UTC  diverse USA gezien
raar tijdstip voor USA  beste was Alabama en KC0  in EM25   ander  pad moeten zijn
lange pad kan toch niet vanuit noord Nederland?


Druk met 23cm  reparatie alweer vocht in de voeding boven.
Corrosie  door water indringing bij een vorige lekka…