23cm on two Watts and a prayer

A few month back one of the members of my radio club posted to the clubs group.io group that he had participated in the April 23cm UKAC using a his new IC9700 and a tri-band vertical and managed three OSO's.    

His foray into the world of 23cm's had me dusting off my SG-Labs 23cm transverter I had bought a few years previous and had sat on the shelf and actually give it a whirl. 

The transverter is the MKII version and has a power output of 2.5W so real QRP compared to the IC9700's 10W.  The only antenna I had was a similar tri-band (Comet GP-95N) with a gain of 12.8dBi if you believe that?  The feeder was 15m of Ecoflex 10 so feed losses were going to be around 2.47dB.   So all things considered ERP would be around 16.5W.    

Using an FT817 with the above setup I entered my first 23cm UKAC and was amazed to work 7 stations with the best DX being G3MEH at 105km.  

I can't remember now if I used the ON4KST microwave chat during the first contest but I believe I didn't but with all subsequent contests I did.  

Anyway I was actually amazed I did so well with such low power and polarisation mismatch but that one contest had given me the incentive to do the next contest.

For the June contest I made the easiest change I could and bought an 18 element Yagi a  PA1296-18-1.5RB from Antenna Amplifier in Serbia.  The antenna gives a reported gain of 17.16dBi this of course gave me an increase in ERP from 16.5W to 45W which should give me improvement of around half an S-point and of course the 30dB improvement from having no polarisation mismatch. 

You can see from the table below there has been a steady improvement in points and DX though in August there was some great tropo as shown by the fact I worked OZ1FF on 2W though it was mainly sea path but neither the less I was extremely happy.

Month	QSO's	Points	DX Km
May	7	1877	105
June	11	2154	105
July	11	3070	180
August	11	3624	208
September	19	8357	670

So the next easy upgrade will be replacing the current feed cable with Ultraflex 13 but that will only yield another dB but it will be in place for the October contest.   

Next up will be finishing off the 80W amplifier I'm building and sticking it in a box.     The finished unit will have a LPF by John G3XDY, a 80W PA based up John G4BAO well known design with a homebrew controller to switch the pa and tvrx while also displaying output power, temp and VSWR. 

QO-100 VFO display for Elecraft K3s and Yaesu FT817

I've been using SDR-Console to listen to QO100 and now I've almost completed my uplink equipment I want some way of seeing what the uplink frequency should be when tuned to a particular downlink one so I knocked up a quick Python script to show me what the uplink and downlink frequency would be when tuning my Elecraft K3s or FT817.

To use it you'll need Python 3 with PyQt5 and PySerial installed.   

Edit the config.ini and set the LO in Hertz which in my case was my 70cm so 432000000

Example:

[CONFIG] LO = 432000000 PORT = COM10 BAUD = 38400 POLL = 0.01 RIG = K3S

To start the application from the command line do. 

python QO100uplinkVFO.py

If that'll be useful you can download the software from GitHub.

   

Your stations crap why can't you hear me?

When I moved to the Isle of Sheppey radio gaining my amateur radio licence wasn't on my mind I was doing some radio astronomy taking hydrogen line measurements of the milkyway so I didn't buy a property with the idea of operating a VHF/UHF station from it.

I've had a number of comments in the 2m UKAC with why can't you hear me? Your station is crap.

Well there's a couple of reasons.

1. The noise floor at this location is around -125dBm all year round and in fact in winter is can be even higher.
2. The tropology of the location.

Well number is primary worse than it was due to stacking the antennas and I still need to get someone up on the mast to understack the array for me.    

Number two however is obviously nothing I can change short of moving house and I'm not doing that.    

My QTH is around 40m above sea level and to boot I live on the side of a hill, consequently in certain directions I have a great take off and in others I might as well unplug the antenna and use a wet piece of string. 

Anyway to show the issue I've taken some tropology profiles which hopefully should show why if you live towards the East of my location I have such trouble in hearing you. 😀

North

45 Degrees

East

135 Degrees

South

225 Degrees

West

315 Degrees

You can see the take off in all directions on the HeyWhatsThat website.

First two months of moon bounce operations

I finally became QRV on 2m EME on the 9th of November 2019 with my first QSO with K9MRI.

I wasn't exactly trying to have a QSO but Joseph popped up on the waterfall as was so strong I thought what the hell I'd give ago and low and behold we managed my first QSO, happy days!

My system isn't yet optimised and in fact I suffer with a lot of local QRM which is hampering activity  but I think with some modifications to the antenna system in the new year should help greatly.

A pre-amp may be worth trying but I think there's probably to much noise here to able to use one but only time will see.

Anyway here's my first dozen EME QSO's.

Date Time	Time	Callsign	Locator	Distance
------	------	------	------	------
09/11/19	23:13	K9MRI	EN70IU	6352km
17/11/19	00:17	UA3PTW	KO93BS	2506km
07/12/19	16:17	RX1AS	KO59XW	2143km
08/12/19	16:49	I2FAK	JN45OB	943km
08/12/19	19:27	UR3EE	KN88DC	2552km
11/12/19	19:32	HB9Q	JN47CG	709km
11/12/19	19:49	S52LM	JN65TX	1119km
14/12/19	21:05	I3MEK	JN55SJ	1038km
14/12/19	21:15	RK3FG	KO86HP	2380km

First EME QSO.

I've just spent a couple of days listening to the moon and getting nowhere using WSJT-X.

When I use WSJT-X with the K3s I have a hell of time trying to the get the RX levels right with the K3s LIN OUT set to 1 the PC Microphone level is set at 0.4dB the RX level indicator in WSJTX is still at 60dB and I haven't a clue why, anyway the upshot is I only had a couple of decodes.

Anyway I switched to MSHV and low and behold multi decodes within 60 minutes of using it, yippie!

So with half an hour before bed I noticed K9MRI in EN70IU and thought what the heck I'd give it ago not expecting much with such a small antenna array and low and behold we completed.

I'm now off to party it's been a hard slog getting that first QSO via EME and I'm ecstatic or should that be over the moon?

First EME contact with K9MRI.