This is actually a nice amplifier that should be quite easy to build for the experienced engineer and experimenter. The benefit of using lower anode voltages is that the tank circuit capacitors can be of a low cost variable type. The PSU can also be integrated more easily in the same cabinet as the amplifier circuit. You can check out more information over at PA0FRI’s webpages: http://pa0fri.home.xs4all.nl/Lineairs/Frinear150/fri150eng.htm

Finally Elfa has increased their range of SMD lab kits. It is somewhat difficult to select the kits from their webpage (that detoriated after they started to use SAP). The manufacturer Nova has a website with better information. You can check out the resistor kit pictured above here http://www.nova-elektronik.de/en/compcards/chip0805.php 

Nova also has capacitor kits. Their SMC-36 kit contains 6030 pcs. SMD ceramic capacitors in size 0603. (6 mil x 3 mil). The range is E6 to 4,7pF with CØG dielectricum. Then they have a 6,6 pF to cover the gap and after that the kits includes the E12 series up to 680 pF. This also CØG dielectricum. Wikipedia has some info about C0G diectricum here: http://en.wikipedia.org/wiki/Ceramic_capacitor You can probably use < pF values up to approx 1400 Mc/s (Megacycles per second = 1/p = Megahertz, p= period) before hitting the self resonant frequency.

By the way the information in Elfas catalog is inaccurate in a lot of areas so make sure to do research before you order from them. For example they stated that the above resistors can dissipate 1W. The manufacturers datasheet says 0,1W. Only a factor of 10 wrong. (Probably due to that incompetent spotty teenagers are making their catalogs these days, instead of engineers?)

Mark over at www.brainwagon.org has posted some interesting info about sending hellschreiber from an Arduino (see Marks image above). He has used KD1JVs oscillator circuit that was originally used for the wireless morse code thermometer project. Mark has written code for the Atmel Tiny 13A uC for Hellschreiber transmission. You can find code on his website. Below you can study the schematic designed by KD1JV ( you can find more info over at KD1JVs site http://kd1jv.qrpradio.com/temp2morse/temp2morse.htm).

The way this circuit works is that the XTAL oscillator (left) is powered on and off via PB3 output from the Atmel uC. The emitter of the 2N3904 has been tapped with a 6” antenna. Here a DS18B20 Maxim temp chip is used for accurate temp sensing. The temp is sent out via Hellschreiber together with the callsign. The circuit could be expanded with a buffer tapping the signal from the emitter of Q1. That buffer could feed a power amplifier (well filtered of course). Then a Hellschreiber telemetry beacon could be set up. Cool idea!

Tony CT1FFU and Diogo CT2IRW has released a converter for the Fun Cube dongle. The design is a based on the old NE602 workhorse. One new approach is to use a wideband MMIC amp in the front end. The unit is powered via a USB connector. Looks like this may be a good add on if you want to do some basic HF monitoring with the Fun Cube. You can find more information here: http://www.ct1ffu.com/site/index.php?option=com_content&view=article&id=178&Itemid=104

This picture (above) gives a good overview over the antennas at OH8X. You can see the M7 and the M1 towers stand out. Notice how small the M6 rotatable tower looks. The M6 tower in not small in real life its 32m high.

This is how a real stack should look (above). Notice the icy elements. The orange cables inside the tower is for operating the ice knockers that keeps the elements free from ice and snow. (Snow turns to ice etc). The tower is fully rotatable.

This is the 5 el yagi on 80, 3 el yagi on 160 and 4 over 4 on 40 (above). The tower is rotatable. It weighs approx. 40 tonnes. The rotor sits in the bottom of the tower and the rotator gearbox is BIG!

This is the correspondent LB3HC calling in to the shack (via cellphone and not VHF for the occasion) to ask for a rotator turning operation to check proper rotation of the tower before the ARRL CW contest. The tower in my view that is… (behind the camera). The other towers speaks for themselves in the background.

The guys that built this station are extremely skilled. Kudos and congratulations to the Arcala team!
You can find more information here: www.radioarcala.com

FlexRadio systems is launching new products and new improved software all the time. I have been following the SDR scene for several years now and experimenting with the Softrock 40 and softrock RX-TX as well as some earlier VHF SDRs has been fun.

I must say that the offerings from flex-radio is now becoming more tempting than many offerings from traditional suppliers like Yaesu and Icom. My FT-2000 with the latest software is surely a great radio (the best I have had so far) but I think a FLEX-5000A with diversity RX and the newest PowerSDR software must soon be tried in a serious contest effort. The filters, diversity functions and FFT bandscope functions are simply great. One thing that lacks are the feel of real buttons and controls. But that has also been taken care of (read below)

Here you can see a video from Flex-Radio where they take the new tracking notch filters (TNF-RF)  for a spin:

In case you lack the feeling of a real radio, DH1TW is here demonstrating the use of a DJ controller for adjusting VFO and other radio functions:

Surely great stuff! Stay tuned!

The www.funcubedongle.com webpage is a bit unclear about how to do the upgrade, so here I have written up how to upgrade the software.

1 ) Goto www.funcubedongle.com

2 ) Select downloads

3 ) Download Windows fully functional front end

4 ) Download Boot loader with source code

5 ) Unzip those two archives in a suitable directory. (If you need a free zip tool, you can use the free WinRar software that you can download from Rarlabs homepage http://www.rarlab.com/ )

6 ) Make sure you close all other SDR programs that may acess the funcube dongle. This is important so that the funcube is not “occupied” by another program

7 ) Plug in your funcube dongle to one of your USB ports

8 ) Wait 10 secs and listen for the “bling” sound that windows sends to signal that a new USB unit was detected

9 ) Start the FCHID.exe file (the front end)

You should now see something like this –>

10 ) Click the read device. You should now NOT see any error message. In case the read went ok, you now have a connection to your funcube dongle

11 ) You now want to set the funcube dongle in the bootloader mode. This means that the funcube is ready to boot from new software.

Here comes the confusing part: you must start another piece of software to upload the new firmware to the funcube. You cannot do that from the FCHID.exe file. The software you use for uploading the firmware is FCHIDBL.exe

12) Start FCHIDBL.exe (from the CHIDBL___Win32_Debug subdirectory where you unzipped the Boot loader with source code ) file from point 4) above

13) Download the latest firmware from Firmware v18i – Save it to the same directory as you saved the other files.  NOTE per Jan 2012 this was the latest software but this may have changed when you read this !!! Check what is the latest file before you upgrade!

14) Now start the FCHIDBL.exe file. You should see something like this:

15) Click the Open file button

16) Select the *.bin file you saved earlier (the *.bin file contains the firmware)

17 ) At this point -> if you are on a laptop make sure your laptop battery is OK or that the laptop is plugged into a AC adapter, so that you don’t risk that your laptop shuts down while you flash the firmware to the Funcube dongle.

18 ) Click WRITE FIRMWARE button. Now click RESET TO APP to get out of boot loader mode (Thanks to Jeff Murri for this tip).

19 ) Close both programs you opened earlier

20 ) Wait 10 secs (just in case)

21 ) Plug out the funcube dongle  (Probably overkill, but hey…)

22 ) Wait 10 secs (to let windows have time to unload the driver. Not sure if this is really necessary. But hey …..)

23 ) Plug in the funcube dongle again

24 ) Congratulations, you have upgraded to the latest firmware !

I have recently acquired a Funcube dongle software defined radio. The Funcube dongle is a small USB unit that contains a E4000 Silicon Tuner (radio on a chip), a TLV320AIC3104 Audio Codec and a Microchip 24FJ32GB002 16bit Microcontroller. This small USB device gives me coverage from 64 to 1700 Mhz with some small gaps according to the manufacturers data. You can download more information here: http://www.funcubedongle.com

As a windows SDR RX I am at the moment experimenting with the sdr-radio program that you can download here: http://www.sdr-radio.com

The picture above shows a FM broadcast transmitter in the Oslo area. You can also see the pilot carrier that is used to encode the stereo information if you look carefully

By processing the data from the STEREO satellites that are positioned “behind” and to “the side” of the sun, it is possible to plot the solar winds that are emitted from the sun.
You can check it out here: http://www.swpc.noaa.gov/wsa-enlil/cme-based/
The sun and the earth as well as the two STEREO satellites are seen from above in the circular images above. The green spot is the earth. The yellow spot is the sun. The grayish spot is the stereo satellite that sees the emissions from the sun before any active areas has rotated towards the earth. The red spot is the stereo satellite that sees the emissions from sun after any active area has rotated thru the earth direction.

The fan shaped images to in the center of the image above is the sun and earth seen “from the side”. It is possible to check if the emissions from the sun will propagate above, below or towards the earth. The AZ images on the left alone are not enough, because a particle emission may have the direction of the earth in zimuth (seen from the sun) but may have too high an elevation or too low an elevation to hit the earth.

Schematic:

Curves:

According to an Eimac engineering note, the maximum energy the grid circuit of a typical Eimac YC-179 or 8877 can take is 4 Joules. With only a fuse and a glitch resistor it looks like it will be hard to prevent the grid taking less than 4 Joules of energy. A typical Elschukom HV fuse opens after 10ms at 10x rated current according Elschukom datasheets. This is too long time to prevent the tube becoming damaged, if Eimacs data is not too conservative. I suspect the opening time will be less if loaded by 100-200x the rated current. I have contacted Elschukom engineering department to get more data.

In this simulation I have taken the time integral of the current x voltage product to investigate energy dissipation in Joules. (A not very well documented trick in LTspice is to CTRL+left click on the trace you would like to investigate to get the numerical time itegral of the trace data. If the trace data is a compound statement, the integral engine will give you correct units. For example P in Watts x t in seconds will give you Joules).

The findings in this simulation may be incorrect. Please contact me if you have comments or would like to share experiences from practical field tests.

Instructions:
===========

If you want to disable the crowbar to see dissipation with just a glitch resistor, just change R1 to 10 MEG.

If you want to change the PSU DC voltage, right click V1 and change to desired value.

In case you would like to increase the capacitance of the capacitor bank, right click C1 and enter your new value.

If you want to change timings, please change pulse sources (they control the voltage controlled switches to simulate the sequencing in a real HV PSU).

You can download the simulation files here:
hv_crowbar_switch_test_with_tube.asc

Here is the LTspice plot settings control file (Rename the file so it has a .plt extension and load it via Plot Settings / Open Plot Settings file) :
energy_in_glitch_res_and_tube.txt

These files are licensed to you free of charge for hobby use. If you change them you have to share the results back. If you would like to use these files for commercial design / R&D purposes, please contact the author for more information.