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Friday, 26 August 2016

QED on the Birds!

Well,

Following my last post here, I've managed to complete my first Satellite QSO.

I'm using SatPC32 to control the antennas and also the Radio:


My first QSO was with RN6MA in LN06uo - Thanks Victor!

We were using the XW-2A satellite; uplink on 435 MHz and downlink on 145 MHz.


So much to learn!

Local conditions.

Monday, 22 August 2016

Some More Bird Time!

Well,

Following the progress last time, today I have finished the LVB Tracker kit.

The kit is complete and the programming of the PIC done; I had some issues with this part of the project. I couldn't get the PicProg executable as supplied as part of the fileset to function - it would appear to program OK, but the verification failed. There were way too many variables involved so I dug out the PIC programmer I purchased way back when and programmed the PIC that way. Once I had figured out all the configuration bit settings I was up and running....


The image above was taken during the calibration process. Basically the rotator control box outputs two voltages which are representative of the position of the AZ (0-360) and EL (0-180). You tell the software when the rotator is at 0 in both AZ and EL and then again when in 360 and 180. It can then calculate the appropriate voltage for anything in between.

I've chosen to use SatPC32 software for tracking the birds, controlling the rotator and also handling CAT control of the radio to automatically turn the antennas (both AZ and EL) when a selected satellite is in reach, and also control the frequency setting on the radio - including the adjustment for Doppler shift as the bird is moving towards or away from my station.


Here's a quick video of my first ever reception from an Amateur satellite. This is before getting the CAT control functional - just the antennas are moving automatically to track the bird as it passes:


And here is a quick video showing the auto tuning for Doppler (no sound):


So now it's time to do some research and some listening before I decide which satellite and how to make my first QSO. Fun egh?

Here's Miss Luna Cat asleep behind one of my monitors:


Local conditions.

Sunday, 21 August 2016

Following the Birds!

Well,

For quite some time I have wanted to try my hand at Amateur Satellites. Now, I plan to utilise my IC-9100 for this task - it is a full duplex radio meaning I can TX on one band whilst RX on the other.

I decided I would build myself a "proper" satellite tracking antennamabob, and here it is up in the air:


There's 3 elements on 144Mhz and 7 elements on 70cm. The antenna has both azimuth and elevation rotation capabilities using one of these:


It's a Yaesu G-5500 rotator; unfortunately they don't supply the necessary hardware to separate the azimuth and elevation rotators - so I had to fabricate something suitable. I've mounted the azimuth rotator way down the pole and utilising these brackets from Barenco and a Yaesu thrust bearing we have a suitable working arrangement with minimum weight at the top.

The plan is to develop a means of automatically controlling the antennas such that they will auto track satellites using PC based software. I've bought one of these kits from AMSAT, here in early construction:


And here ready to wire up and start to play:


So, lots to follow on this topic!

Here are a few of the feline family members:


Good, egh? Local conditions.

Friday, 29 July 2016

It doesnt get more Bonkers!!!!

Well,

You may recall that some time ago, myself and Vince, G0ORC, set up a Wires-X repeater.

This has been an endless cause of headaches as it has continually suffered lock-ups in FM TX mode since we connected it to the Wires-X network and the big bad Internet. It's odd that the TX lock is in FM mode because the repeater is configured in Digital only.

Having tried many re-flash of the firmware in the repeater, different network connections, updating firmware in the HRI-200, operating with a chicken down my trousers whilst facing north and also changing the version of Wires-X software on the PC, even sending the repeater back to Yaesu - we have finally given up.

We can't find what causes the TX lock-up nor can we stop it.

So we now have the most Bonkers solution I can think of - this is a £300 solution to a problem that shouldn't exist.



So instead of connecting the repeater to the Wires-X network using a HRI-200 and PC as it is designed to do, we are connecting via RF to a nother radio using a dummy load! We have a separate node configured to TX on the repeater input and RX on the repeater output, the repeater is now configured as a stand alone digital only repeater. The only connectivity between the two is via RF through a dummy load on the "node" radio; which is a FTM-100D configured as a Wires-X node.

Quite ridiculous, egh?

Here's our beautiful Bonnie Dog - she's now 8 months and 29 days old and quite fab.


Local conditions.

Sunday, 17 July 2016

SDR with the Red Pitaya

Well,

I came accross this board on the RS Components website, it's called a Red Pitaya:


Now this board is very much designed with RF and SDR (Software Defined Radio) in mind, it's got some very high speed ADCs (Analogue to Digital Converters) and DACs (Digital to Analogue Converters) on board - it also has a SoC (System On a Chip) with an ARM processor and a FPGA (field programmable gate array) pluis a whole other bunch of useful stuff also on-board.

Now, there's a very clever chap Pavel Demin who has written some fab and groovey software for the board to try a whole bunch of stuff from a simple SDR receiver all the way to a VNA (Vector Network Analyser). There has also been some interesting introductory articles to the board published in the Data Modes column in Practical Wireless.

I've been playing with the WSPR decoding software as a starter-for-10.

You have to go and get the software from the website here. You can download an image of the Red Pitaya boot device (memory card) and create the memory card for the device to boot from - I used Win32DiskImager for Windows - you could also use DD for Linux.

Once you have that device created you can boot the board from the card, then you need to access the board from your network - I used Advanced IP Scanner to find the board and then used Putty to create a SSH connection. From there it was a simple task of editiing the decode-wspr.sh file, adding my callsign and grid square and then rebooting.

I have the board configured (by editing the write-c2-files.cfg file) to decode 8 bands similtaneously (yes that's correct).

Here's a map of my decodes with the Windom connected to the input connector of the Red Pitaya (via a small attenuator pad for impedence matching).


I've also tried the SDR Receiver software with HDSDR configured to conenct to the RedPitaya SDR accross the network - it worked superbly.

I now intend to try to get the TX side of the SDR functioning - using WSPR first. To facilitate this we will need a bit more hardware. I found a great buffer amplifier design by SV1AFN here. I ordered the PCB only from him and here's the finished article (I am one SMA connector short of a party):


I'll also need a TX RX switch which I will create using a latching SMA relay I have here and a kit from W6PQL.


To move on to the VNA experiments I will need some other bits and bobs including this:


So, much more to follow!

Here' our Choppsy cat (AKA Git Basterd Cat from Hell):


Good, egh? Local conditions.

Saturday, 25 June 2016

New Amplifiermabob

Well,

I've been thinking for a while about upgrading the amplifiers I have here for 4/6M and also 2M. Here's the result of my investment:






The 950 deliveres 1KW on 6M (500W on 4M) and the 1000 is 1KW on 2M. Both solid state amplifiers from Beko in Germany.

Given the termoil on the currency markets as a result of Brexit - I might have just timed this right.

Local conditions.

Sunday, 19 June 2016

I've made another one!

Well,

You may recall the recent Frequency Reference that I made, I've just finished building another one for someone else! This one is almost identical except I have included a 1MHz low pass filter as this one will be configured to have a 1MHz fixed output.






Here's the 1MHz output:




Good, egh?