Thursday, 4 February 2016

G3PYB -SK

I am off to Havant in Hampshire tomorrow. Peter's funeral is on Saturday morning and to avoid an early start from over here in Suffolk I thought I would stay over Friday night at the hotel where the post funeral reception was to be held.  It turns out that a number of other microwavers and ATV enthusiasts had the same idea. I only just managed to get a room!
There will be, among memorial items, a QSL board where we will be able to place our QSL cards. 
This seems to be a popular idea and has been seen at several memorial receptions over the last few years. 

I haven't been in the Havant area for many years and I'm looking forward to seeing it again, albeit in somewhat sad circumstances.

Thursday, 31 December 2015

Lunch in Cambridge

Excellent New Year's eve lunch with some of the Cambridge hams at Horningsea today.
Lots of talk about EME and testing systems. This was quite relevant as I have been playing with MAP65 over the last few days. I want to be able to monitor the 40-50kHz of 23cm where the JT65C activity is located.


MAP65 on 2m EME

My previous attempts at getting MAP65 to work have been unsuccessful. Recently I became aware that it was possible to use the SDR-IQ on the IF output of the K3 with SDR-Radio as the interface to MAP65. My attempts to get it to work were getting nowhere until I spoke to G4IDR.  Dave talked me through setting it up. I had not spotted a small icon on the SDR-Radio screen. Once pointed out it was possible to start MAP65 and send data packets to it.

Tuning the K3 to the 144MHz beacon band it spotted and listed GB3VHF. Clicking on the display trace of GB3VHF produced a decode of the beacon.

After this I reconnected the 9 element yagi and masthead preamp and left the yagi pointed towards were the moon would rise in a few hours. 

15 minutes after moonrise I came back to see a whole load of stations listed, including RRs and 73.
Several of the stations were obviously direct terrestrial signals from the nearer continent, but at least three were by moon reflection from their DT timing on the decoded display. All in all I was pleased with this result and I'm now looking forward to connecting to my 23cm Eme system and looking at how many signals I can decode on that band/mode.


Monday, 21 December 2015

Some low noise tests

Merry Christmas,
I had intended to work on my EME dish today. However, the weather has been very wet and windy since mid morning. Consequently I decided to do some measurements on the LNA with a view to reducing my EME system noise temperature on 23cm.

After (re)reading a number of interesting articles on noise figure reduction by SM5BSZ and RW3BP I thought that I would measure the insertion loss of my LNA protection relays. These are SMA types by one of a number of manufacturers and all are surplus ( second user) SMA types with 3  in-line SMA female connectors. All are12V working.

After carefully calibrating my HP8753C network analyser ( warmed up for several hours) i found that the best I could do was 0.071dB insrtion loss from a Totsoel with 0.1dB from a Teledyne CCR 33S80
I must stress these are used relays. I have to use what I have!

The net result of using the Totsoel relay with an SMA90 bend to the feed and SMA male back to back adapter between the relay and VLNA is 0.38dB as a noise figure.
This is quite good but I believe I can improve on it using some of the techniques describd by RW3BP.
The back to back adapter can either be eliminated completely or replaced with a modified version using a piece of UT141. The probe to relay connection can be made in one piece to eliminate yet another SMA connector.
Now to try a few of thse ideas.

Sam


Saturday, 14 November 2015

Kangaroo Island

  
Back from Tasmania for a few days and went to Kangaroo Island. The island is 20km off Cape Jervis, south of Adelaide.
Two nights in Kingscote allowed us to visit Flinders Chase Wilderness area at the western end of the island and an hour or so from Kingscote.

Admirals arch and the New Zealand fur seals were first.

 Followed by the remarkable rocks


 
The heritage walk behind the Visitor centre provided both koalas and kangaroos





Sam










Saturday, 7 November 2015

And on to Burnie

We hadn't planned to visit Burnie, but as it turned out, we have!
After crossing more mountainous terrain we found ourselves near Devonport. From there we just sort of wandered along the northern coast as far as Boat Harbour Beach. Beautiful white sands.
As we had already booked into a hotel in Burnie, we wondered back here. At dusk we are going to wander over to the Glade and see if there are any platypus around this evening.

Wallabies and wombats



More anon

Sam
Here at Cradle Mountain, Tasmania, we are surrounded by wildlife. Wallabies abound (pardon the pun) around our cabin at the Lodge, and wombats roam freely.

Wallaby outside the cabin


As was this guy!

We visited the nearby Devil's Cradle to see the Tasmanian devils and quolls


And no view would be complete without this fellow wondering along the roadside





Tuesday, 3 November 2015

Visiting VK7

We have been in VK for several days and are currently in Hobart. VK7MO kindly agreed we could stay at his QTH for a couple of nights and Rex has shown us around his fine city including a trip uo to the very top of Mount Wellington. Although it is now Spring down here it rained heavily yesterday, up on Mount Wellington it had fallen as snow. In consequence  it was extra cold at 1270m!

Yes, that is Hobart down below.........

L
Rex and I have had long talks about 10 and 24GHz EME and the benefits of portable EME operation at these frequencies.




Tomorrow we will set off for Queenstown and Strachan. The weather promises to be better later this week.



This is one view from Rex' QTH, towards the east and out towards the Tasman peninsula and Port Arthur.

Sam