- 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.
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.
