AmateurLogic 120: Raspberry Pi for PC & Mac


AmateurLogic.TV Episode 120 is now available for download.

George installs Raspberry Pi Desktop for PC and Mac.
Tommy visits John Amodeo on the new set of Tim Allen’s Last Man Standing. Watch it come together.
Emile shows the long awaited, multifunction, PiClock.
October will be ALTV’s 13th Anniversary. We are celebrating with another contest. Get all the details here.

1:21:16

Download
YouTube


George Thomas, W5JDX, is co-host of AmateurLogic.TV, an original amateur radio video program hosted by George Thomas (W5JDX), Tommy Martin (N5ZNO), Peter Berrett (VK3PB), and Emile Diodene (KE5QKR). Contact him at [email protected].

MiniTiouner DATV Receiver built

At the weekend I built my MiniTiouner DATV receiver. I'd purchased the PCB, tuner module, 1V regulator and programmed USB interface module from the BATC stand at the Telford ATV Academy the previous weekend. The remaining components that I didn't already have were ordered from Digikey using the handy spreadsheet on the BATC Wiki and I sourced a suitable DC-DC Converter from eBay.

The build was straightforward and there are some instructions by Mike G0MJW but only really referenced them for the commissioning stage, checking voltages etc. I was pleasantly surprised to see a large degree of protection on the board, fuses both filament and poly-fuse, reverse protection and zener diodes in the circuit.


The MiniTiouner uses free to download DVB-S receive and analysis software called "Minitioune" written by F6DZP. The Software is hosted on the VivaDATV forum. So I registered and downloaded the software.

V8.0 of the software requires a pull-down resistor adding to the USB module to identify the type of board, so that was added (not pictured).

Power was connected and then plugged the USB lead into the PC (Windows 7 32bit) and it went off and installed drivers. The documentation said I should see two USB controllers, but I was seeing four?

There are several test programs included in the software package to test drivers and board and they were showing errors.



The PC I was using has had no end of serial USB devices plugged in and out over time so suspecting another Microsoft Windows "disappearing up its own backside" driver issue I tried it on another more vanilla machine but had the same problem.

This seemed to point to the USB interface (an FTDI FT2232H Mini Module) perhaps it wasn't programmed? So I downloaded the FTProg utility from FTDI but instead of seeing a FT2232H was showing it as a FT4232H device.


Doing a Google found a reference to the same problem. I downloaded the data-sheet and checking with a meter I could see pins CN2-5 and CN2-11(VIO) on the module didn't have 3.3V for some reason and as the post said if the VIO pin is missing 3.3V it defaults to a FT4232H. In the end I checked my soldering (no fault found) I removed the module from the socket to examine it and after re-seating it the board sprang to life so seems it was just a bad connection.

Eager to test I set up the ADALM-PLUTO SDR running DATVExpress as I'd done previously with the commercial set-top satellite receiver and we had a picture! It was time for a cup of tea!


Now it was working all that was left was to put it in a box.


I have only had a brief play with the software since the weekend but was interested to see if I could receive some RB-TV (Reduced bandwidth) So I set the Pluto and DATVExpress to transmit on 146.500MHz using a low symbol rate (250 Ksymbols/s) and it worked!  Bertie was wriggling a bit too much for a clear picture but I had now actually used my 146-147MHz NoV. Now just got to learn and understand the various modulations and settings.


I was able to try out another piece of software, the Spectrum Analyser from Steve Andrew for the SDRPlay. It turns the SDR receiver into a handy spectrum analyser with 10MHz bandwidth from 1kHz upto 2GHz and was able to check the output of the Pluto.

 
This wasn't a proper test setup by any means, the SDRPlay was still connected to the dual-band collinear outside the shack so the noise is the usual hash I see, but the Pluto was putting out a decent waveform, it did help putting on a proper resonant antenna (a spare mobile magmount) rather than the tiny one supplied.

I plan to do a bit more with the 5.6GHz FPV stuff before the weekend having took delivery of some nice grid antennas and hope to get out to try a contact or some tests with members of SKARS 73

Andrew Garratt, MØNRD, is a regular contributor to AmateurRadio.com and writes from East Midlands, England. Contact him at [email protected].

Recent Noise Mystery Solved

 
You may recall a recent blog regarding my installation of a new pair of inverted-V dipoles, fed from a common coaxial feedline at around 85'. Both antennas 'hear' very well and everything was peachy until I recently put the inverted-V's on my Perseus SDR.



I had been particularly interested in using the new high antennas for my general shortwave listening on 40m and below but what I observed was immediately troubling when listening on the 5 - 6MHz, 49m band. After much head-scratching about what I had noticed, I posted the following 'help' message to the Perseus reflector as well as to the Perseus SDR Facebook site:

Perhaps others can help explain something odd that I have just noticed with my Perseus while comparing antennas.

I was comparing signal levels and noise between a 40m half sloper and a very high dual 40/80m pair of inverted-V dipoles fed from a common feedline. Both the sloper and the dipoles are fed with 50 ohm cable and all three antennas are well matched at the low end of the band(s).

Listening to a 6 MHz signal from China National Radio around 10 am today, the signal was around S7-8 on the Perseus, using the 40m sloper. Listening to the same signal, at the same time, on the Yaesu FT-1000mp, with the high inverted-V, it was slightly better, maybe by 5-6 db and overall lower noise. I then put the inverted-V onto the Perseus and there was not even a trace of the signal! I made this check with several signals and always with the same result.

Now I suspect that the SWR of the 7MHz inverted-V when used at 6MHz, is very high and the load presented to the Perseus antenna input is likely highly reactive and far from 50 ohms but that doesn't seem to bother the FT-1000.

I then ran the inverted-V through my antenna tuner so that it effectively produced a 50 ohm non-reactive input load for the Perseus and did the tests again...with the same results. Swapping antennas for the 40m sloper once again produced the same signal levels in both the Perseus and the FT-1000.

So what is going on here and why does the Perseus balk at the 7 MHz inverted-V while listening on 6 MHz? Is there something in the Perseus front-end analog filtering system that is overly sensitive even though the reactance was tuned out via the tuner? Is it the 80m V on the same feedline as the 40m V that is causing some still unwanted reactance that is not tuned out with the tuner?

Any ideas what is happening here as it looks like I will not be able to use the inverted-V antennas on the Perseus for general SWL out-of-band listening for some, as yet unknown, reason.



As you can see, I was completely mystified by what I was hearing, or rather not hearing, and as it turned out, completely off the mark.

I received a few replies offering some possible reasons for what I was seeing but none of them proved helpful in solving my dilemma ... until Roelof Bakker (PAØRDT) weighed-in! Roelof suggested that I look at the antenna's performance while running Perseus's built-in 'HFSpan' function.

HFSpan is a stand-alone 0-40MHz spectrum analyzer, that comes with the Perseus software. Although I was aware of it, I have only used it sparingly. I next did some screen captures with all three antennas, one at a time, and sent them to Roelof.

His analysis did not take long as he immediately identified my problem ... a very high noise floor when using the mysteriously-performing inverted-V. Roelof suggested some common mode choking to eliminate the problem.

Already having an isolating transformer in hand from a previous experiment, I inserted it directly at the Perseus antenna input and looked at the noise floor again, around 40m. The transformer was wound on a small FT87-J core with a 3 turn primary directly opposite a 3 turn secondary. I was astounded to see the background noise floor drop from -85dbm to a very quiet -110dbm!

Evidently there was a lot of noise being picked-up on the inverted-V's feedline shield. Not hearing any of this noise on the FT-1000 indicated that the noise was probably associated with the Perseus power supply, the laptop or the laptop's power supply. This immediately explained why I wasn't hearing anything with this antenna when used with the Perseus.

Roelof then suggested that a 2 turn / 2 turn transformer, offering less inter-winding capacitive coupling, might provide even more isolation ... and he was right again. A further ~4dbm lowering of the ambient noise was measured.

It may not be pretty but it produced an astounding improvement!

Further comparisons between the FT-1000 and the Perseus revealed that the FT-1000 was still producing a slightly better SNR than the Perseus, when using the inverted-V so evidently there was still some noise affecting the signal. I had a few very large #43 ferrite toroids and decided to wrap a few turns (5) of the RG8-X feedline around the toroid to see if there would be any improvement.

Once again, using HFSpan, I compared the noise floor both with and without the #43 choke and saw a further 6-7 dbm improvement! Going back to comparing SNRs between the FT-1000 and the Perseus, I now saw no difference between how I was hearing on both receivers, when using the troublesome inverted-V ... eureka!
Here are the 'before' and 'after' screen shots using HFSpan, the Perseus built-in spectrum analyzer. Both screen shots were taken at the same time (mid-afternoon) and show the results of the noise mitigation work.

0-10MHz sweep - with noise problems
Same sweep, noise eliminated, signals now unmasked

As of yet, I have not determined the actual noise source. I suspected it may have been coming from the Perseus power supply or from the laptop supply but that was not the case. Perhaps it is coming from the laptop's processor via the USB cable which I will also choke and see if HFSpan reveals anything further

This problem was a great learning experience for me, in more ways than one and I am most grateful to Roelof for his detective work and experience with noise issues and for taking the time to respond to my initial inquiry. Hopefully you may find something here that can help you as well.

Steve McDonald, VE7SL, is a regular contributor to AmateurRadio.com and writes from British Columbia, Canada. Contact him at [email protected].

Pikes Peak SOTA: Hike from Devils Playground

Stock photo of Pikes Peak with snow on it.

I’ve been up Pikes Peak (W0C/FR-004) a zillion times via the Pikes Peak Highway and the Pikes Peak Cog Railway (currently out of service) doing SOTA activations, working VHF contests, participating in the Colorado 14er Event, maintaining repeaters and escorting visitors from out of town. See my previous post on activating by driving up the mountain: How To Do a SOTA Activation on Pikes Peak.

Joyce/K0JJW and I had Pikes on our SOTA activation list for 2018 but wanted to do a hike to access the summit. The classic climbing route up Pikes is via Barr Trail, a 13-mile trail that ascends 7800 vertical feet. This is a difficult climb for most humans but I will note that serious runners routinely run up the mountain just for fun. See Fred/KT5X’s comments on the SOTA database about running up the mountain and then doing a SOTA activation.

Another hiking alternative on the northwest side of Pikes Peak is the Crags Trail, also known as the Northwest Slopes route. This route starts about 4 miles south of Divide, CO at the Crags Campground. This hike is 7 miles one-way with 4300 vertical feet. This is easier than Barr Trail but still a significant climb.

The hiking route from Devils Playground to the summit of Pikes Peak.

Devils Playground

There is a shorter option that does not get much attention (except from some of the locals). The Northwest Slopes route crosses the Pikes Peak Highway at Mile 16 at a popular spot called Devils Playground. There is a large parking area there and the Northwest Slopes trail can be accessed at this point. Just cross the road, step over a cable fence (intended to block vehicles, not people) and follow the obvious trail to the summit.

Note: currently access to the summit by car is restricted due to summit house construction and Devils Playground is a staging area for free shuttle buses that take visitors to the summit.

This trail is 2.6 miles one way and 1300 feet vertical (mostly uphill but some up and down action). The last quarter mile before the summit is rocky and steep. The trail becomes more difficult to follow at this point but careful attention to the cairns will keep you on the right path. As shown on the map, this trail tends to stay close to the road so you will see vehicles along the way. All in all, this was a nice hike on a good trail.

Once on top, we set up our standard 2m FM station: Yaesu FT-90 and the Arrow 3-element yagi antenna. We quickly had a pileup on 146.52 MHz. It is kind of crazy up there when everyone starts calling because you are hearing everyone but the chasers are not.

Bob/K0NR using the Alinco HT and the PC board yagi to make a 1.2 GHz radio contact.

It was great to work Steve/WG0AT on Mt Herman (W0C/FR-063)  and Brad/WA6MM on Mount Morrison (W0C/FR-092). I also worked Paul/W0RW on 1.2 GHz with my Alinco HT driving a two-element yagi PC-board antenna.  (A quick comparison between the rubber duck and the yagi confirmed that the yagi does have some gain.) We ended up in a bit of a hurry as the clouds moved in but tried to work everyone we could. Our best DX on 2m FM was Dave/N0KM near Del Norte, about 100 miles away. On our way down, the clouds were in and out but no storms or lightning.

All of the usual warnings apply for hiking above treeline: start early and get off the mountain before the storms move in.

73 Bob K0NR

The post Pikes Peak SOTA: Hike from Devils Playground appeared first on The KØNR Radio Site.


Bob Witte, KØNR, is a regular contributor to AmateurRadio.com and writes from Colorado, USA. Contact him at [email protected].

Amateur Radio Weekly – Issue 214

All about Ham Radio
An introduction to the world of amateur radio.
SparkFun

JumboSpot DMR Hotspot
One of the latest crazes in the world of DMR radio is the Chinese iteration of the DMR hotspot. The principal attraction? Low cost. The Jumbospot costs about $45.
John Hagensieker

Light Up 2 Meters Night, an FM Simplex Event
August 26, 2018 7-9pm local time.
K5ACL

Radio hams at DEF CON 26
DEF CON 26 is taking place August 9-15 in Las Vegas and radio amateurs will be there giving presentations on HAARP, amateur satellite communications, and SDR’s.
Southgate

DIY vs. commercially made solar panel
The price of commercially made solar panels on eBay is around $1 per watt and have been for a few years, but the price of individual solar cells are likewise at a low price per watt, around $0.48.
Hack A Day

Receiving GOES weather satellite with a 2.4 GHz WiFi grid antenna
GOES 15/16/17 are geosynchronous weather satellites that beam back high resolution weather images and data.
RTL-SDR.com

Moving Pictures: First dabbles in Amateur TV
I’ve spent the last couple of weeks experimenting with some Amateur Television ATV and Digital ATV.
AmateurRadio.com

Wisconsin residents embrace Amateur Radio
An estimated 2 million people are on the airways worldwide, according to the American Radio Relay League. About 830,000 amateur radio stations are located across North, Central, and South America alone.
U.S. News

A primer on grounding for Hams
Nothing like a fierce electrical storm to get Hams talking about susceptibility to lightning strikes. Well, we experienced just such a storm in early August, which provides the perfect opportunity to review the topic.
VE7SAR

Video

Building a multi-band HF dipole antenna
Here I build a multi-band dipole antenna for HF use on 40-20-15-10-6 meters. Some call this a fan dipole.
RadioHamGuy

Nashville Amateur Radio Club Field Day 2018
NARC Field Day 2018 at Lock 2 Park, Nashville, TN
K4CPO

Get Amateur Radio Weekly in your inbox.

Sign-up here


Amateur Radio Weekly is curated by Cale Mooth K4HCK. Sign up free to receive ham radio's most relevant news, projects, technology and events by e-mail each week at http://www.hamweekly.com.

Forward thinking and food for thought.

Sorry there has been very little activity from me during the last few months, family stuff has taken up a lot of my spare time recently, and radio has been well off the menu. However I will try and get back into the Blog as our Summer comes to an end.

I was recently contacted by one of the Telford Hamfest organisers asking me to give a talk:

 We would like to invite you to give a "talk" at our "Telford Hamfest" QRP, orientated, would be great. The date for our Hamfest is Sunday September 2nd 2018. We expect to put on three "Talks". The "Talks" would last about 40(ish), minutes, with a Q&A after each, with a gap until the next talk. The timings are 11.30,12.30 and 13.30. I hope you are able to take us up on our offer Steve
--------------------

The Telford Hamfest is a Radio rally which has been held around the Telford area for many years at various venues. But for a number of years has stabilised at being held at Coalbrookdale, Shropshire, and also now incorporates the G-QRP Convention as an added bonus.

Well Stephen had already decided he wasn't going to the Hamfest this year, so it all arrived too late! But it is with interesting thought what I would of talked about, and who actually put me up for this, I could name a few?

The last lecture I gave is when I ran a Packet radio BBS and node (GB7RUG) some 20 years ago. Talks don't just come together overnight, sorry I had no real time to prepare anyway. So Telford Radio club and G-QRP thanks for asking, I might do it next year if you give me enough time to think about it?

Actually by now I have mulled it over I have even thought in my dreams what I would of chatted about Hmmm! Humm!

See you all next year :-)



Steve, G1KQH, is a regular contributor to AmateurRadio.com and writes from England. Contact him at [email protected].

K5A Special Event Station

Screenshot from 2018-08-10 08-40-25

On Saturday, August 11, 2018, the Bella Vista Radio Club will be operating a special event station at the Shiloh Museum of Ozark History in Springdale Arkansas. This is to celebrate the 50th year anniversary of the museum. We will be operating on the museum grounds from the General Store. Listen for us on the air starting Aug 11, at 1300Z. Operations will conclude at 2300Z.  Two stations, one SSB and the other CW, will be operating on or near 14.250, 14.035, 7.250 and 7.035.

I will be participating part of the day, likely on the SSB station. I may spend some time trying to listen to CW to see if I can decode it yet! Gotta work on that!

For more information see the following links:
ARRL Link
Bella Vista Radio Club Link

Looking forward to having a QSO with you on Saturday!

 

 


Wayne Patton, K5UNX, is a regular contributor to AmateurRadio.com and writes from Arkansas, USA. Contact him at [email protected].

Subscribe FREE to AmateurRadio.com's
Amateur Radio Newsletter

 
We never share your e-mail address.



Do you like to write?
Interesting project to share?
Helpful tips and ideas for other hams?

Submit an article and we will review it for publication on AmateurRadio.com!

Are you a reporter covering ham radio?
Find ham radio experts for your story.

How to Set Up a Ham Radio Blog
Get started in less than 15 minutes!


  • Matt W1MST, Managing Editor

Sign up for our free
Amateur Radio Newsletter

Enter your e-mail address: