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K3 144XVTR 60m wspr

PTT connected to KEY-OUT pin10  180R  protection. 13.3V to main single pin power
(on board 220R are used to pass signals to the ACC pins as protection )  SMA  144 port

Building this 144MHz XVTR  into the K3 project kept me in the warm shack.
Since the nice summer type weather ended here last Friday the sky turned grey and we
are back to cool windy rainy weather.
Same time ES dx Disappeared
I now strong believe the ES clouds are fed with sunny sommer weather gasses that rise up into the ionosphere...
Some time ago i bought the "Ukrainian"   XVTR 144MHz
 And now it works,  had  first contact's at 144.174  in FT8 !
I seached some victim for the first 144MHz contact,  the whole 144- 146 empty
but still life ? or should i say robots active... on FT8 144.174

Meanwhile weather has changed again in to summer  and so  the propagation.
Since the K3 144 transverter is running I had remarkable good results with it and the home brew 7ele + 5 ele 4M duoband
Lots of 2m DX  heard and worked with 10W since then
EI3KD 1050km   GI GD G7RAU -IO79 905km  OZ SM LA GM3FVM almost daily!
SM6 7  SP OK F HB9 heard DL  in JN68 2x  OY6BEC heard 144  70Mhz and 1296.895 mni days
Easy working  DX that used to be so hard in the past 1980's  when I was very active at 2m 
This season was almost without 144 ES but therefore great tropo.

Delivered quick  by Transverter-shop on  eBay even better deal.
Very well designed  high quality at low prize. It is very small and fits nicely into the K3 cabinet.
Transverters never have been so affordable ready build.
When I compare my 6m 4m and 23cm Xverter project's , nice experience but it took months and a lot  € to get on air.
It's mounted on an aluminium plate 86x50x10 using  2x  M2.5   attention M3 does not fit
86mm fits exactly between the side and KPA100 plate. I drilled carefully.. 2 3.2mm holes in the side plate 2 M3 hold the whole XVTR it can be removed very easy 
High efficient  RD15HVF1 Mitsubishi FET 10W RF @ 13V 1.3A about.
Real 10W RF  ,0.5V  drop over the connection wire and 2  header pins
Frequency stability is remarkable good with the  54MHz cristal.  XV2 OFS 144  -2.25
Most (all?) X-tal resonate a few kHz above the wanted frequency, no issue it is compensated with XVx OFS  -2.25 for me.
No drift  running WSPR or FT8
If more stability would be needed i would replace the X-tal with a Taitien VCXO if available.
Very good experience with  TAITIEN 27MHz VCXO rock stable standalone 23cm PLL 1150MHz.
Unnecessary worried about cooling issues, the XVTR stay's cool after some 45 minutes FT8 tx-ing . No need for a big heatsink  this 10x86x50 does the job easilly.
Easy to set up a 2nd XVTR in the K3 config  the 1rst is my  external 70MHz XVTR.
The output level of the KVX3 max 1.5mW  is more then sufficient,  1mW for full drive.

Some issues i came across:
At start the PTT-out did not work when it was connected also to the HF ACOM1000 KEY-IN.
The ACOM Key-in loads the PTT line to 5V in open state.
RX 8V  was not switched in, so the RX was very deaf at first test
After unplugging the ACOM this was okay.
This is solved by connecting the XVTR PTT to atn other KEY-out signal at K3IO pin 10
This KEY-OUT  is a true open collector in RX state  RX is switched  at 8V    7.3V measured.

unsolved yet:    this is solved using some diodes and transistor logic
Automatically  switching 13.6V  power and 28MHz port between the internal 2m and external 4m XVTR  at band change does not work.
I find no hardware options on the KXV3  to make automatic switching of transverters possible
The KXV144 from Elecraft must use the AUXBUS  and the i.f. 28MHz port and power must be switched off and separated internally.
DIGOUT0 is set low when XVTR low power is true  this is valid  for all XVTR's using KVX3 DIGOUT0 can not be selected per band
I might need an AUXBUS address decoder to solve this issue.
Until now i could not find information about the AUXBUS  data format. User groups possible but not yet found i can not work with user groups it seems.
Measured serial approx 2400b/s data burst  at band change  5V TTL fan out is low.

Do i have to reinvent the wheel and experiment with Arduino / Pic to make a band decoder
Or did  someone  reading this already made such AUXBUS decoder ?
preferably a decoder that does not contribute negative to the noisefloor...
It is low speed serial data so the decoder clock does not have to be higher then a few kHz...

Both XVTRS use KVX3 port XVTR-IN for 28MHz Tx/Rx
The  2nd XVTR-OUT port is TX only  i have an older KXV3 that has no TMP sockets for internal XVTR's
Paralleling  results in extra noise and loss of 28MHz signal.
When TX-ing at one band the other XVTR is also TX-ing.
I have not yet found a way to use the DIGOUT 0 -1 to select 1 of 2 XVTR's
DIGOUT-1 is already in use to switch between 160m/80m antenna
The output that the manual refers to for use with XVRT's  is DIGOUT-0
Is low active level when  XVTR band is selected i.e. all XVTRS set this port active
and high for all other cases  ie all other bands not using KVX3 XVTR options  DIGOUT0 can not be programmed in config
So Both 4m and 2m have DIGOUT-0 low so that does not help.

The config setting XVx ADR  can select trn1-9 and  Int. trn0-9 AUXBUS adresses  al lot addresses!
 but it can not select DIGOUT1 or 2 or BAND or XVTR port

The hardware of the KXV3 has 2 relays
 K1 is used to bypass ANT-IN ANT-OUT or switch them to the RF board
K2   is used to bypass XVTR-IN OUT or switch them to RF board
when a (any) XVERTER is activated in config and the band selects that XVTR the relay swiches the ports to the RF board. Then XVTR-IN works tranceive at the chosen i.f. im my case 28MHz
the tx level is max "150" # 1.5mW
the XVTR-OUT  is TX out only
this is as far as i could understand the K3 schematic
The 12V ( i.e. 13.3V) power is connected as pointed out in Elecraft manual for K144XVTR  to the single pin soldered at the main PCB 12V. This 12V is unswitched. So the XVTR stays powered
In the K3s  newer type there is a connector named XV12V  could be  swiched

The Elecraft KXV144 uses a BUS controller over the AUX-BUS  several XVTRS are adressable.
Modern rigs all use internal device busses like I2C .  Nice but  a data bus can  buzz.
The K3 internal bus generates  a rattle bus noise when tuning the dial with antenna open at 50MHz
Best is to avoid use of fast databus and or controllers in low noise devices i think
The AUXBUS is a slow speed telemetry 2400b/s?  type bus it is activated upon band change
Need to find a decoding circuit for it.

So far so good.

215042 Tx 521 ~ G8EOH PA0O -13
215045 1 0.1 673 ~ CQ G8EOH JO02
215100 Tx 521 ~ G8EOH PA0O -13
215115 -2 0.1 672 ~ CQ G8EOH JO02
215130 Tx 521 ~ G8EOH PA0O -13
215145 -5 0.1 672 ~ PA0O G8EOH R-12
215200 Tx 521 ~ G8EOH PA0O RRR
215215 -11 -0.7 676 ~ PA0O G8EOH R-12
215230 Tx 521 ~ G8EOH PA0O RRR
215245 -10 0.1 678 ~ PA0O G8EOH R-12
215300 Tx 521 ~ G8EOH PA0O RRR
215315 -9 0.1 681 ~ PA0O G8EOH R-12
215330 Tx 521 ~ G8EOH PA0O RRR
215345 -4 0.1 683 ~ PA0O G8EOH R-12
215400 Tx 521 ~ G8EOH PA0O RRR
215430 Tx 521 ~ G8EOH PA0O RRR
215445 4 0.1 685 ~ PA0O G8EOH 73
215500 Tx 521 ~ G8EOH PA0O 73
215530 Tx 521 ~ 1 QSO K3+XVTR
215545 -5 0.1 689 ~ CQ G8EOH JO02

Propagation 60m WSPR

Bands are poor but some JA7 weak heard at 50.313MHz Thursday
Temperature dropped 25C to 14C  rain and wind 7bf
Also 50MHz Es is gone now  .... 6m rule in the weekend no propagation still valid...

But it can not be that bad  every day DP0GVN  Southpole base  spots 1W  and tonight  0.5W
 WSPR signal at 5354.70 kHz 60m
 2018-06-23 23:02  OZ7IT  5.288747  -18  0  JO65df  5  DP0GVN  IB59uh  14097  188 
 2018-06-23 23:40  OZ7IT  5.288747  -17  0  JO65df  5  DP0GVN  IB59uh  14097  188 
 2018-06-23 23:20  OZ7IT  5.288747  -18  0  JO65df  5  DP0GVN  IB59uh  14097  188 
 2018-06-23 23:08  OV1MK  5.288706  -19  0  JO65bb  5  DP0GVN  IB59uh  14077  188 
 2018-06-23 23:36  PA0O  5.366166  -17  0  JO33hg  0.5  DP0GVN  IB59uh  13835  186 
 2018-06-23 23:06  PA0O  5.366166  -23  0  JO33hg  0.5  DP0GVN  IB59uh  13835  186 
 2018-06-23 23:16  PA0O  5.366166  -15  0  JO33hg  0.5  DP0GVN  IB59uh  13835  186 
 2018-06-23 22:56  PA0O  5.366167  -14  0  JO33hg  1  DP0GVN  IB59uh  13835  186 
 2018-06-23 23:04  DL4XJ  5.366196  -20  0  JO42un  2  DP0GVN  IB59uh  13780  187 
 2018-06-23 23:24  DL4XJ  5.366197  -18  0  JO42un  2  DP0GVN  IB59uh  13780  187 
 2018-06-23 23:22  G8VDQ  5.288647  -22  0  IO91um  5  DP0GVN  IB59uh  13604  183 
 2018-06-23 23:24  G4ZFQ  5.366265  -20  0  IO90ir  1  DP0GVN  IB59uh  13513  183 


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