Posts Tagged ‘pixie’
Since my post earlier on this blog about low cost 40m Pixie kits from the Far East, I have been told that Bangood was selling these kits today for a staggeringly low price! This information is thanks to Spence M0STO. Earlier they were for sale at an incredible £2.67.
At this price you might just buy the crystal here in the UK! The kit comes with ALL parts (apart from battery, key and headphones) and a very nice silk-screened PCB. Don’t forget this is with FREE shipping. Unbelievable.
My kit from them worked first time. It was the first time I’d built anything in a LONG time because of my stroke. At this price it is an offer too good to turn down. AM breakthrough was perfectly usable (i.e. low) and RX sensitivity fine. I got over 400mW out too. Don’t forget, this is a complete 40m CW transceiver.
Sorry for the double post but the kits are here and the Customer Service is second to none. Beware the prices change daily inline with currency. http://www.banggood.com/DIY-
Radio-40M-CW-Shortwave- Transmitter-Kit-Receiver-7_ 023-7_026MHz-p-973111.html
Steve, G1KQH has pointed me to a link with 40m Pixie kits at incredible prices. At these prices there is no way the parts could be bought for less than the kit. The version I bought for $10 looks identical. All you need is a morse key, battery 40m antenna and walkman type headphones and you have a credible 40m CW transceiver. It really works.
Now I back in front of the Pixie bargain game hunt, after finding the the best price!!!
and if you buy more than 2 it gets cheaper!!
Not forgetting this includes free shipping. Unbelievable.
|My assembled 40m Pixie|
The Pixie is a very simple HF transceiver. Usual power out is in the 200-1000mW region, depending on band and DC power source. It was first developed some years ago but the basic concept is using a PA transistor as a mixer in a simple direct-conversion receiver. On TX this is used as the TX PA.
Being simple, it has a number of limitations but it certainly works. A major issue can be AM broadcast breakthrough, although my 40m version is perfectly usable. I was very impressed with my little kit that came with all parts including a silk-screened PCB, all sockets and a crystal. It needed low-Z Walkman type headphones, a morse key and battery – that was all. On 40m the sensitivity is pretty good with 0.5uV clearly audible and my RF power out is around 400mW. A lack of both RF and AF RX selectivity is also noticeable.
Kits are available from several sources at prices that are hard to beat. I recently bought a kit for $10 with free airmail from China. It is available for less than half this price I subsequently found out. Unbelievable for a fully functional HF transceiver. Of course, being so simple you may prefer just to build it dead-bug fashion. I bought a kit as I wanted to see how my building skills were.
As a mature design, it has been through several iterations, some improve the basic design, but most do so at the expense of increased complexity. You’d be hard pressed to find a circuit for a complete HF CW transceiver much simpler.
I bought my 40m Pixie kit for $10 and thought this was a bargain. Then Andy Cutland sent me this link.
Hi Roger, this is the cheapest i’ve seen yet. What fantastic value !Check out this item I found on eBay:End time: 15 Apr 2015 10:33:10(Sent from eBay Mobile for Android)
At £3.19 with free shipping there is no way you could make this cheaper in my view. Remember this price includes a crystal, PCB and all the board mounted parts. This looks identical to mine which works very well. This is a refined Pixie and performance has exceeded expectations. Netting is excellent TX to RX and AM breakthrough very modest. My power out is about 400mW and a 1uV signal level very good on RX. A totally usable 40m CW rig for not much more than a cup of coffee.
Even with the after-effects of my cerebellum brain bleed I was able to build the kit without any issues.
|Pixie harmonic measurements|
This afternoon I visited G6ALB to do some more accurate measurements of my completed 40m Pixie kit. Power out with the 12V battery was 400mW and with a fresh PP3 9V battery 200mW. On the 12V battery TX current is around 129mA and at 9V around 83mA. 2nd harmonic rejection was about 20dB. Even the 9V output is a useful level. Maybe the cased unit should include an internal 9V battery pack which is switched off when an external 12V pack is available?
|Pixie on the bench|
To be more useful, I should add a 7.030MHz crystal and have a switch to select this or the original 7.023MHz one. 7.030MHz is the QRP frequency. My experience is this can be quite busy.
I should also case the unit! Drilling the case could be a challenge in my current state of health! Just doing the building and testing was exhausting.
At 1000z this morning I exchanged RST 579 reports with G6ALB who is 3km from me on my 40m Pixie on 7.023MHz CW. This was my first on-air QSO. Netting was perfect and I used the rig directly into my low Par triband antenna. An ATU might have helped. Andrew G6ALB said the channel was pretty busy but that I was a good RST579 with no hint of chirp. This afternoon we’ll put the rig on his spectrum analyser. I gave Andrew 579 probably reflecting the poorer MDS of the Pixie. I have no idea of his power or antenna.
My initial goals have been met: I built the kit and have managed a QSO on the air with it. With the fatigue associated with my brain bleed still very apparent (I am well and truly shattered currently), I was well pleased. A few more QSOs with the 40m Pixie would be good, HI.
$10 well spent. Excellent little kit. FB little transceiver. Works surprisingly well.
Well, it took a super-human effort on my part as a result of my extreme fatigue (brain bleed issue) but today I bench tested the little 40m Pixie kit I managed to build earlier this week. It is hard to explain just how exhausting this simple task was for me currently. I now need to recover my energy!
On receive a 1uV signal was perfectly readable and I could detect carrier on/off down to at least below 0.5uV. On TX it was putting out about 250mW into a 50 ohm load. On my antenna it was suffering some AM breakthrough, but less than I was expecting. I was using standard Walkman stereo headphones and a rechargeable 12V sealed lead acid battery. On a small 9V battery I’d expect about 100mW RF out, although this was not tried.
Overall, these results exceeded my expectations: it is more sensitive than I was expecting and the breakthrough of AM broadcasters is certainly OK in the day time. This is of course with no casing at all and no ATU. Using the fitted pot and fitted 1N4001 as a varicap it is easy to get the TX frequency and RX frequency to correspond, often an issue with very simple QRP rigs.
Next stage will be some on-air tests, but it most definitely works. Working the locals should certainly be possible. Sked with G6ALB (3km) arranged for 1000z Sunday on 7.023MHz CW.
UPDATE 2120z: There is a contest in full swing and several Russians and Asiatic Russians copied on the little 40m Pixie. I did not stay on long but there was no apparent BC interference noticeable. So, on a quiet night I should able to use the rig in the evenings. The main issue on RX seems to be the lack of AF filtering, so one has to use “the filter that is between the ears” i.e.the brain.