I write this as asked a few questions about my name on the Elecraft UK builders list.... http://www.elecraft.com/k2_builders.htmI don't get paid by them to build for anyone and I don't pay them to include me on the list.Exchange with one amateur from UK and I am building his K1 right now:> I hope you don't mind me asing... I wonder how much you charge for your services? I am just in the process of buying a K1-4 and unfortunately...
Wednesday, April 25, 2012
So I am an Elecraft builder what does that mean?
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Sunday, April 22, 2012
SDR
I saw this and thought was hillarious (grabbed from here http://xkcd.com/730/ and http://xkcd.com/643/)In addition working a lot with Simon HB9DRV and SDR-RADIO.com building the MOBOKIT V4.3 for him to u...
Thursday, April 19, 2012
Wireless FM Transmitter
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circuit >>
rf >>
schematic >>
wireless fm transmitter >>
wireless transmitter
This wireless FM transmitter is designed to use an input from another sound source and transmits on the commercial FM band. This low power fm radio transmitter it is actually quite powerful. The first stage is the oscillator, and is tuned with the variable capacitor. Select an unused frequency, and carefully adjust C3 until the background...
More TZ-20 Amplifier
Labels:
RF Amp
With the chassis and front panel drilled, punched and painted this project should start looking more like a kit. Everything is in hand, all I need to do is mount, wire and solder.I laid out the chassis and front panel so that eventually this amplifier will serve as an upper deck of a 70 watt CW transmitter. My 1934 transmitter will be the...
My Dissertation: Open Source SCADA System
Just a quick note to say that I've uploaded my dissertation to SourceForge. It is an open source, Java based SCADA package.SourceForge link is: https://sourceforge.net/projects/ocpscada/And the wiki link is: http://sourceforge.net/apps/mediawiki/ocpscada/More details will follow, I'm sick of typing by now - I just spent the day filling my w...
Sunday, April 15, 2012
RF Power Amplifier 80W 2SC2782
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circuit >>
FM Power Amplifier >>
Power Amplifier >>
rf >>
schematic
This is a conventional FM RF power amplifier design, using bipolar transistors in a tuned class C circuit. Thanks to the use of two stages, the amplifier can be driven to full power with less than 1 watt driving power, so that a large gain margin results in this FM transmitter. Bipolar VHF power transistors have a severe affinity for...
SDR talk/demos
Done a couple of rally table/stall demos of SDR radios and asked about which ones to get/buy/build... In addition to some notes on software for the softrock SDR radios from Tony Parks KB9YIG I'll document some notes and ad them to the blog short...
Loch Erne Rally 11th April 2010 (Enniskillen, Northern Ireland)
Just got back.Photos of the table showing the SDR demos I ran.I also managed some /P operation from the rally as MI1KTA/P into a 20m dipole and then on the trip back on two afternoons from the beach near Dublin as EI/M1KTA/P and managed several 2xqrp contacts. Worked qrp DX included RA1CW and 4X4...
Friday, April 13, 2012
Springtime - QRPtime
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qrpxpedition
With an early spring here in SE Minnesota I can start thinking about QRP again. One of my favorite local picnic table QRP spots here in Rochester is Essex Park. It has plenty of space, lots of trees with limbs about right for antenna supports and movable picnic tables. Take a look here for a video on my operating from Essex park. On Saturday I worked N1LU, Don in NH, and K1TG, Roger in CT. K1TG was an especially good QSO. We...
Monday, April 9, 2012
Thursday, April 5, 2012
Loch Erne (Enniskillen) Rally 11th April
Just getting the display of kits ready.Cannot bring the whole shack so in the box will be (everything I have soldered from kits):The web links are current and provide info on them, some not from vendor.HB-1A / Direct from BD4RG http://k1hah.net/HB-1A-MK-II.htmlPFR-3 / http://www.qrpkits.com/pfr3.htmlATS-3B / KD1JV http://kd1jv.qrpradio.com/ATS3B/ats3b.HTMMKARS80...
Wednesday, April 4, 2012
EnsembleTRX with HB9DRV SDR-Radio Beta
Just finished building and here is a short video of it worki...
EnsembleTRX PA
The final stage of construction.I built this for 80m and 40m and T3 and T4 are small and the windings tight.In both cases the bifilar Secondary(T3) and the bifilar Primary (T4) are wound first with the single wire winding being added last. You may find this a little easier.Now usually if this were a V6.2 or V6.3 I would have added a drop...
EnsembleTRX TX Mixer (QSE)
This is 1 SMT Ic and 4 SMT C underneath and on top an additional transformer (T2) and inductor (L1), 9 resistors, 3 C and a couple transistors.I had to substitute in for one of the 220pF caps (C...
EnsembleTRX TX Op Amps
TopBottomThe TX op amps are two identical sets of components for the I & Q channels to create 0,90,180amd 270 degree inputs to the TX mixer, fed from a single 3.5mm stereo sock...
EnsembleTRX PTT switching and RX circuit
OK this caused me a few headaches as one BS170 was duff and so the PTT from the AVR USB was not functioning.So I replaced the Q10 BS170 and it is now functioning fine. Lesson in there for anyone building one... watch the BS170!Now to place the RX OP amps (actually just one IC but dual OP amps) already placed the RX mixer FST3253.That is the...
Tuesday, April 3, 2012
EnsembleTRX PTT
OK PTT... managed to get it worked out using Rocky... using cw mode (feel like an idiot as had tried using SSB!) Anyway on PTT in Rocky I get 5V on pin3 of the AVR. Good so far.With no PTT enabled on the galvanically isolated RF side at the opto output with R36 and R34 in place to tap into the 13.8V line I get 10.71V (13.8V supply) at R51, enable PTT and R51 drops to 0.09V. OK that seems fine.However if I follow the voltage...
Softrock Ensemble TRX Modification to the Si570 output.
Modification needed for the Si570 output.Tony just let me know CLK+ (pin 4) should be connected via a 0.1uF and not direct to T1."...Mike Collins did a design review on the RXTX Ensemble and pointed out the a direct connection to the CLK+ output of the Si570 is not allowed in the manufactures spec of the part. The fix is to cut the trace...
Homebrew Bench Video
Been asked if I have a home brew bench video.... so connected up a cheap web cam I had lying about and just pointed it at the home brew bench. This is just me tinning a new iron t...
Monday, April 2, 2012
Softrock Ensemble TRX Beta Build Divider
Now the LO has been tested as working as reported in previous blog posts (I have not uploaded a video yet showing the LO frequency tests, but I will.. it does work!)Now to build and test the dividers.As per Robby's website:The Dividers stage takes in the local oscillator's signal and divides it by 4, producing two output signals. Each output...
Softrock Ensemble TRX Beta Build LO test
Now the LO is built have to test it.Download and install SDR programs and Dynamic Link Libraries, along with hardware drivers. The actual steps anyone else might follow will vary, depending upon the operating system etc.PE0FKO (Fred) CFGSR Configure/Control Ensemble microcontroller softwarePE0FKO (Fred) SRDLL dll for Softrock controllersThe...
Soldering Si570 to softrock boards
I took this to explain how to solder the Si570 chip in place.The 8 pins 6 are large 2 are tiny.The tiny pads getting these wrong causes about 99.99% of the problems with the Si570 not working as expect...
Softrock Ensemble TRX Beta Build
I started this here:http://rf.circuitlab.org/2012/03/new-sdr-trx-from-tony-parks-beta-build.htmlAnyway here are some photos: (BTW the boards will look terrible as I have not cleaned them up removing all the flux etc)The reverse is of the pcb was not silk screened so here I ID the componentsFirst thing build the power supplies.The 5V one is...
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