Extreme, wow that's Extremely Extreme!

Well,

Thinking about Lindy that I made back here:

http://g0mgx.blogspot.co.uk/2013/12/whos-lindenblad-i-wonder.html

I ordered a 144-145 MHz pre-amp kit from Amsat-UK:

http://shop.amsat.org.uk/shop/catalog/browse

The design was published in September 2012 OSCAR News.

I've done quite a bit of SMD kit building in the past, AKA Extreme Soldering - but this was a whole new challenge! The components in this were the smallest I've ever come across - this was really tricky!

The image above should open in quite high-res so you can see the effort I have made of the soldering. It's quite poor really, but it certainly works as you can see below. The odd looking peaks on the far left of the spectrum are harmonics from my 10MHz frequency reference (I think):

It's already mounted in a die-cast box and the power is fed down the coax. This should work directly with my FT-847 which can provide coax based power to external pre-amplifiers.

I'll have to see how the satellite passes look tomorrow with this amplifier in-line - ideally I should mount this at mast head end of the coax to amplify any signals that are lost in the coax run. I've got about 20 meters of Westflex 103 and the losses at 145MHz are quoted at 4.5dB per 100M. I make that a possible loss of 0.9dB. Let's try using it at the shack end and see what happens.

Interesting, egh?

So much for Windy, How's Lindy?

Well,

That antenna I finished making back here:

http://g0mgx.blogspot.co.uk/2013/12/lindy-is-up-in-air.html

Despite the bad weather and all the other distractions, there's just been a overhead satellite pass of funcube whilst I was in the shack. Here's the telemetry I received from the satellite:

Now, the bird wasn't the strongest signal on 2M that I have ever heard, but it was certainly stronger on the Lindy antenna that it was on the colinear. So first test of Lindy - Pass!

Good, egh?

Lindy is up in the Air!

Well,

Remember the antenna I was describing back here:

http://g0mgx.blogspot.co.uk/2013/12/whos-lindenblad-i-wonder.html

I've finished it and stuck it up in the air:

The antenna analyser thingamabob suggests that the actual resonant point of the antenna is about 149MHz, but the SWR at 145.9 MHz is still only 1.4:1.

If I stick the antenna on the RLB I started to make here:

http://g0mgx.blogspot.co.uk/2013/09/return-loss-bridge-where-does-it-lead.html

Then this is what we see:

I explained the trace we see above using the Return Loss Bridge with the Spectrum Analyser back here:

http://g0mgx.blogspot.co.uk/2013/10/so-lets-get-bit-smarter.html

So there is a definite resonate point at 150.7Mhz, but there is also a very good match at 144.5MHz, at my target frequency of 145.9 the SWR is 1.38:1 which is perfectly acceptable.

Whilst I have been up and down ladders today, the cat has been completely useless as per normal:

Fun, egh?

Who's Lindenblad I wonder?

Well,

Since the launch of the new cubesat Funcube-1:

http://funcube.org.uk/

I've been watching the path of the satellite while I've been in the shack (tracking it with logger32) and downloaded telemetry data on a number of the birds passes using the funcube dashboard (available on the link above).

I've only been using a vertical "white stick" that I have on the side of the house, and the antenna is far from optimum for listening to Low Earth Orbiting Satellites (LEOs).

So, I did some research and found this:

http://n3ujj.com/manuals/Lindenblad-2meters.pdf

This is an easy to construct Lindenblad antenna - designed specifically for LEOs reception. Now, "easy to construct" for me was not so easy. Anyhow, I ordered the metal I needed and some other bits and bobs and today I have been to see my friend Paul who has a metal workshop. He has helped me cut, bodge, bend, hit and rivet stuff. I've brought all the bits home and assembled something that looks like this:

So what we basically have is four dipoles all slightly non-resonant such that they present a 200 ohm impedance so when they are connected together we end up with a 50 ohm antenna.

The feeder arrangement is rather odd; the pdf linked above suggests soldering the four cables into the N-Type socket but that looked as near to impossible as makes no odds so me - I'm trying this bodged arrangement first!

I'm just off to get the "corporate" antenna analyser that covers 144MHz - then we will see if I have created an antenna or a clothes line of some sort.

Cat's been no use whatsoever today:

Interesting, egh?