OV140 German SDR project

This started from the mcHF project and is an open source software and hardware project from Germany. When it is ready, it should be a very interesting SDR transceiver covering up to 2m with 75W. It is expected to be low cost.

See https://www.youtube.com/watch?v=Tdi0wjO1UwM&feature=youtu.be&t=11282

SDR (Software Defined Radio) book

This is fairly recent book by Andrew Barron ZL3DW. I got my copy recently from the RSGB book shop. Having no experience with SDRs I find the book fascinating. Clearly SDRs are the future.

LimeSDR review

Southgate News has links to a review of the LimeSDR transceiver.

See http://southgatearc.org/news/2018/march/limesdr-mini-software-defined-radio-transceiver.htm#.WqpM30x2vIU .

SDR receivers and transceivers

There is a real gap in my knowledge as I have never once tried an SDR based receiver or transceiver. SDR dongles are very low cost, so I really have no excuse.

On the Southgate site I read news of a new SDR 5W transceiver.

See https://sunsdr.eu/product/sunsdr2-qrp/

RSP2 SDR receiver

SDRplay has announced a new SDR radio. I have to admit never having played with SDR radios yet. This is quite a gap!

See http://swling.com/blog/2016/11/announcing-the-new-sdrplay-rsp2/ .

and

See http://www.sdrplay.com/docs/SDRplayRSP2announcement.pdf  .

New portable SDR transceiver

Amateur Radio Weekly reports on a new portable SDR transceiver due out in August this year. Price is expected to be less than $500.

See http://www.qrpblog.com/2016/04/esdr-new-portable-sdr-hf-transceiver.html?utm_source=amateur-radio-weekly&utm_medium=email&utm_campaign=newsletter

SDR transceivers (more)

Several people have contacted me - thank you for the feedback so far. I have been reminded that the Elecraft KX3 has an SDR architecture and retails from about £850, ready built, in the UK, Of course with all the leads and options it works out considerably more expensive, but it is a very good unit.

SDR transceivers?

Recently I mentioned the 5W SDR transceiver from Italy by Elad which retails for £899 in the UK. This can be used with or without a PC. Clearly with a PC more features are available.

There are several more SDR based transceivers on the market such as the Flex 1500. There are also a few SDR transceiver kits. I wonder if readers have any favourites?

Elad SDR transceiver

From Italy come the news of the Elad SDR transceiver, which was featured in RSGB's RadCom last month. This is being sold in the UK for £899. It is an SDR 5W transceiver covering from 9kHz to 54MHz.  It can be used with or without a PC.  It has 0dBm output at all frequencies and 5W in the amateur bands. Looks a very nice radio.

This image resides on the Elad website and will be removed immediately if copyright is being infringed or having this link is otherwise an issue.

Handheld of the future?

See http://www.southgatearc.org/news/2015/february/ht_of_the_future_at_orlando.htm#.VNi6BC4WKPc .

Southgate News reports that Bruce Perens K6BP will be demonstrating a handheld platform that can cope with many modes at VHF/UHF at the Orlando Hamcation in Florida. This looks like a demonstrator at 100mW RF. With SDRs, quite a flexible, and low cost, architecture is possible.

I wonder which of the "big names" will be first to market with a real SDR design? This could enable them to sell very low cost units, but maybe they would rather shaft us and make big profits?

Portable SDR project

From Pedro:

Good morning Roger look at this fantastic project from Michael KE7HIA  I believe it will be fantastic for some digitals because of the low power.

hackaday.io/project/1538-PortableSDR
 
73 and fast recover

Pedro Almeida
CT5JZX

100kHz - 1.7GHz SDR

This data was passed to me by Steve G1KQH (again). It looks like an SDR in a screened box with proper interfaces. It comes from Hong Kong. Price is £36.99. I have never played with SDS dongles.

See

http://www.ebay.co.uk/itm/100KHz-1-7GHz-full-band-UV-HF-RTL-SDR-USB-Tuner-Receiver-R820T-8232-Ham-Radio-/191241138400?pt=UK_Mobile_Phones_Communication_Ham_Radio_Receivers_Transceivers&hash=item2c86dc30e0

 

Low costs SSB "Pixie" from Argentina

Pedro LU7HZ has sent me an update on work in Argentina on a low cost approach to an HF QRP SSB transceiver using very few parts. Basically they are using simple electronics coupled with an SDR approach to the modulation and demodulation process.  My own approach would be the fully low tech approach (for a CW/DSB rig) but Pedro's approach is innovative and worth watching. I hope he produces kits or, at the least, documentation to allow others to duplicate the idea as it comes to fruition.

Roger,

This is a project we've been working together with Willoh (LW3DYL) which fits partially into your quest for an extremely low cost and easy to build rig ("UKP 20 decent HF...") although not using the low tech approach but the other way around.

The design is still being debugged and more simplifications will be attempted (such as a more simpler TR/RX switch and eliminate the 7474 based quadrature filter replacing it by an RC approach. The net result should be a one IC and 4 transistors design plus PA final.

The design uses an USB power source (out of an inexpensive cell phone switching power supply or straight out of the USB port at the PC) having 0.5W with it; more like 1W with +12V.

Main software platform will be a modified version of KGKSDR. Main use should be CW or SSB although no reason why not to use it with PSK or FreeDV or WSPR.

Should fit on a (small) pocket.

http://lu7hz.blogspot.com.ar/

Main limitation so far is available time from the builders to devote to the project.

73 de Pedro LU7HZ

Dr. Pedro E. Colla
Va.Belgrano-Ciudad de Cordoba
Cordoba- Argentina

"La vida no es esperar a que pase la tormenta, es aprender a bailar bajo la lluvia". Anonimo

Elecraft KX3 manual

The soon to be released KX3 QRP transceiver

The preliminary version of the owner's manual for the latest Elecraft KX3 12W all mode 160-6m SDR portable transceiver is now available. The product is expected to ship very shortly now. Reading the manual it is clear this is a VERY impressive radio packed with features and facilities. Initial reports from field testers confirm performance of this little radio is up there with the very best, and all this in a size not much bigger than the control head of an IC703.

New all-band SDR from Funk Amateur

SDR transceiver PCB assembly

http://www.dh1tw.de/first-pictures-of-allband-software-defined-radio-fa-sdr-trx

The German magazine Funk Amateur has a new all-band 1W SDR transceiver kit in the October edition. This will sell for around $170 US and looks a very interesting project. More details from the link above.

USB powered direct conversion RX

G1INF has a neat idea on his blog for a simple direct conversion RX that is powered from the USB connection of a PC. His application was for LF reception but it would work equally well as the front end of a simple SDR for any HF band, replacing the loop with a bandpass filter. The audio output from the NE602 is connected to the PC's mic connector. Simples!

Mosquito single IRF510 transceiver

EA3GHS and EA3FXF have produced a single IRF510 FET based version of his Mosquito transceiver using a PC as the back end of a software defined radio (SDR). In essence, the FET is used as a regenerative or direct conversion receiver - I think the two are indestinguishable in a single stage RX - with audio coupled to the sound card via a mains transformer which steps up the impedance. The IRF510 is capable of up to about 7W in this application. Coupled with an SDR back-end and this is SOME simple transceiver, especially if the crystal is VXOed.

Web based HF receivers (SDRs)

Web software defined receivers (SDRs) are becoming quite common now. They allow you to eavesdrop on a number of different HF bands and tune around for stations as if you're located at the distant location. The best place to find a list of these receivers is at http://www.websdr.org/ . I have used the one in Twente, Holland to see if my QRP 80m signal got to The Netherlands (it did) and to check activity on bands like 500kHz. Sometimes these SDRs are located in places where the background noise levels are very low too.

Dutch online SDR now has 500kHz

The Twente University online SDR in The Netherlands has now got a 500kHz receiver. It works well and SM6BHZ's SSB beacon was coming through very well a few moments ago.

Web SDR locations

There are now a number of places on the internet where one can find and operate on-line software defined radios (SDRs). For a list of these go to http://www.websdr.org/. One of the best, now streaming 7 different bands, is http://websdr.ewi.utwente.nl:8901/ which is located at Twente in The Netherlands. I have used this one to hear my QRP signals on 40m from the UK. There is a very slight delay but I was able to hear my 400mW signal very well. Another has a recording of the 23cms band during an ARRL EME (moonbounce) contest using a 25m dish: you can tune the band and hear some amazingly strong CW QSOs via the moon.