Nice first E's contact

Sporadic E season is here again!
A bit of luck was on my side yesterday, worked SV5BYR for the first E's contact this season on 50MHz. With the limited power and antenna here I'll probably struggle to do any better E's DX this year but you never know!

Distance between IO81WM & KM46CK is 2916.89 km (1812.558 miles), bearing 113.2 degrees

Homebrew Transciever at G3VRE

Here's a video, made by Jon G0IUE, at our local club. It's my one time 2metre transciever which I've now converted to 6 & 4. More details one day!

MOSFET 50MHz amplifier

I've built a couple of amplifiers recently. This one is for Six Metres, I just followed a design from OZ1PIF's website. It uses eight IRF510 MOSFETs. Output should be up to 250 Watts but I've not driven it hard enough to obtain that amount of power but 10 in produces 150 out so I'm happy with that. Seems to tie in nicely with the figures on OZ1PIF'S site. It's QRP to some but I've rarely run more than 20 Watts on Six from anything home-brewed here and I once worked VK with that.

No front panel meter, no high swr protection, no cooling fan but the MOSFETs are very cheap!

Front panel. The case is from a faulty SMPS.

Meteor scatter signal from DB0FAI

This recording of DB0FAI (144.490MHz) was made at 0825 UTC on 6^th May 2013 via meteor scatter during the Eta Aquarids shower.


The spectacular start to the reception of the beacon is caused by a meteor passing into the E-layer of the ionosphere producing a trail of ionisation that last for many seconds before fizzling out.

Two seconds before the main reflection is a minor one of short duration.


Distance between G8TTI IO81WM & DB0FAI JN58IC is 994.47 km (617.966 miles).I made a large number of recordings very similar to this that morning.

Homebrewed on 70MHz

This is my homebrew Six & Four Metre transceiver. Here working a station during a Four Metre, 70MHz contest. The rig has an SDR output. which can be seen driving #SDR. It has an output of 2 Watts which is enough to drive the homebrew amplifier to 125Watts. Power out on Six is 10Watts which drives 150Watts out of the Six Metre amp.

Inside and tuned to a Six Metre beacon

How I tapped into the first IF and connected my IC706 to an SDRpanadaptor

Lifted from a post I made on my local club website.

Useful search terms for more infomation; Powersdr-if, Ham radio deluxe, homebrew sdr, etc

Below is a video of my home-brewed transceiver for two metres which also has a wide ranging receiver. I recently decided to add an SDR output with a small unit that I developed over a long period of time. It is a fairly straight forward SDR tapped into the IF, which in this case is 10.7MHz.
The unit consists of two diode ring mixers, a twisted wire hybrid directional coupler, which provides both phase shifting and splitter, slightly off tune 10.7Mhz oscillator and a low noise op-amp. If any one is interested I can provide more details at the club. To build should cost less than £10.00 especially if you can find a suitable crystal. The unit is on the right of the rig, slightly raised and can be seen at the end of the video. You could of course buy something like this or a Softrock will do the job.



I don’t have a circuit diagram, I’m afraid it's mostly in the old gray matter!

Next video will be a IC706 with TV dongle connected to the IF, it works very well.

It's quite easy to pick up the 69MHz intermediate frequency in an Icom 706 mk1. There are two plated holes in the track which carry the IF signal so just by inserting the inner of the coax into one of these it can be picked up by the dongle.

The TV dongle accepts this signal and if it is then tuned to 69MHz you are then able to see the IF on the spectrum display and waterfall. The waterfall is not shown here . With the dongle I have here I am able 1.8MHz of spectrum but I can also zoom-in. There are lots of features in the software most impressive is the filtering.

Software used here is SDR#, another that works with the dongle is HDSDR.

So why would you do this? Well it adds a whole new dimension to an otherwise boring black box.

Try it and find out.

There is no reason, of course, why this set-up can not be applied to other rigs with an IF over 60MHz (dongle doesn’t go lower).

UPDATE 04/2014: "SEARCH "RTL DONGLE HF MOD" for info on how to tune it to HF

Hope you find this of interest.

Sorry video's not up to much.

If you want more info ask me at the Club.

 Powersdr-IF and CAT control of the IC706.

I think that this set-up is the most likely to appeal to members.

Here I am using my IC 706 Mk1, the intermediate frequency of which is feed to a home-brewed SDR which I mostly use on Six and Four Metres, so it's ideal to receive the 69MHz IF from the 706.

The software in use here is Ham Radio Deluxe, PowerSDR-IF and Rocky.

HRD is used for the CAT control of the 706. PowerSDR-IF then connects to HRD.

The waterfall display of Rocky is used to view CW, it is not connected to the 706 or the other software, using the sound card output only.

In the video I'm just tuning around the bands mostly using the mouse to click on the spectrum display/pan-adaptor of PowerSDR-IF but also using both the slider and DX-spots of HRD. Of course it's also possible to use the 706 tuning knob but this seems a bit “old hat”.

The pan-adaptor reveals some pretty wide signals, some very clean ones, some with poor carrier suppression, sweepers, odd QRM sources and more. There is no CW filter in the 706 so the SDR output is the only way to receive CW properly.

Hope this is of interest.

If you want more info ask me at the club or post here.

I have been asked by a Club member for infomation on the 1st IF tap point that I used to feed the
RTL TV dongle from my IC706 Mk1.

You should also consider using a buffer amplifier between the rig and the SDR something like a J310 FET should do.

The photos below should help with the tap point.

"It's quite easy to pick up the 69MHz intermediate frequency in an Icom 706 mk1. There are two plated holes in the track which carry the IF signal so just by inserting the inner of the coax into one of these it can be picked up by the dongle."

Use the hole towards the front panel. BE CAREFUL AND TRY IT BEFORE SOLDERING.

Tropo S meter recording of GB3VHF

Here is a recording I made yesterday morning of the signal strength of the GB3VHF beacon which is located in Kent JO01eh as received here near Chippenham IO81wm.  It usually hovers around S6-7 here but there was a clear enhancement yesterday morning. Doubtless more distant repeaters and stations than normal where heard on FM.
The line on the graph is the signal strength of the beacon (-60dBm is S9+10db approx)  time goes right to left so the recording starts at 1140 ends at 1211.
Weather at first was fog with rain arriving round-about 1145 and then getting more persistent.
I think that the drop in conditions is very apparent.

GB3VHF S METER LEVEL

Towards the end of the recording signal strength is bumping along at S5-6 (-90dBm). It's also a lot less stable than earlier.

The regular dips in the trace at the beginning are the WSJT tones sent by the beacon which produce a slightly lower average S meter reading.

SIGNAL INCREASING

This image shows the beacon increasing in signal strength.

Here is the link to the GB3VHF website and more info on this propagation report.
http://www.gb3vhf.co.uk/GB3VHFusingthebeacon.html

Hardware homebrew 144Mhz SDR - Software SDR-Radio by HB9DRV