Archive for the ‘Uncategorized’ Category

Using the RTL-SDR as a transmitter

OK, this is very low power but it shows you what can be done. A QRPP transmitter or signal generator anywhere between 500MHz and 1.5GHz.

Please note the image below is not on my blog (it is linked as shown) and will be immediately removed if this is a problem.

http://rtlsdrblog.rtlsdrblog.netdna-cdn.com/wp-content/uploads/2015/06/transmit_hack_rtlsdr-500×375.jpg

See http://www.rtl-sdr.com/using-the-rtl-sdr-as-a-transmitter/

See also http://www.steila.com/SDR/RFgenmod/index.html .

Amateur Radio Weekly – Issue 65

FCC announce agreement to scale back field office shutdowns
Offices already slated to remain open are New York City; Columbia, Maryland — the site of the Bureau’s HF Direction-Finding Center; Chicago; Atlanta; Miami; Dallas; Los Angeles, and San Francisco.
ARRL

Old VHS recorders could cause long delay echoes
Over the next few weeks, Tommy heard several LDEs, some with separations as much as 3 or 4 days and during this time made several recordings of the events.
VE7SL

A look inside the NR5M super-station
The sun was just setting and I’m sure I had a stupid look on my face as I saw the towers rise over the horizon. What a sight to behold.
W0EA

Another June VHF Contest In the Bag
6m had sporadic-e openings very late both evenings, about the time I was ready to give up. Fortunately, I stuck with it and made quite a few contacts late into the evening.
K0NR

The MS Bike Tour on APRS
Each of the mobiles that were assigned to the various checkpoints with an APRS tracker on board had their APRS trackers programed with a tactical callsign that appeared on the screen of my netbook running APRSIS32 with open-street-maps.
VE6AB

Texas Ham Com – A nice fest that should be the country’s biggest
Look at Hara and then tell someone: “It’s an exciting hobby, just look at this, our biggest event of the year!”
K5PO

When all else fails
The chaos that would ensue would be mind boggling. Not a happy thought.
W2LJ

Baofeng battery test results
The tests were conducted to determine the best long life back-up AA battery solution for the Baofeng HT.
Fo Time! The Other Ham Radio Podcast

Letters to Congress offer biggest boost to Amateur Radio Parity Act
The most useful action radio amateurs can take is to contact their members of Congress, urging them to sign on as a bill cosponsor.
ARRL

Ham Radio can bring Morse Code back to the high seas
Recently, the FCC granted amateurs access to a portion of the historic maritime radio band where most Morse code communication took place. This grant means that people will once again communicate regularly using Morse code around maritime channels at 472, 476, and 478 kHz.
KC4LMD

How to

APRS configuration and testing for a balloon project
We have developed a Pi add-on board and software that together add APRS capability to the Pi In The Sky telemetry board.
Pi in the Sky

Video

Amongst the kilowatts: 14 MHz SSB QRP DX with a delta loop
Have we stumbled across one of the great low-cost antennas for over water portable QRP DXing?
VK3YE

10m – my best band of all

10m has always been my best band. I have lost count of the DXCC totals with QRP SSB. Chasing countries has never been a real activity of mine, although I still get a “kick” from working a new country.

At sunspot peaks it supports world-wide DX with QRP and simple wire antennas. Even in the quiet solar years there is often some DX to be found and usually late April to September there is sporadic-E (Es) to be found with good signals over ranges up to around 1500km and sometimes further. These are for the northern hemisphere.  There tends to be a smaller Es peak around December/January.  It is the reverse in the southern hemisphere. It is quite normal to hear USA stations by Es in the summertime, but usually openings are not for long.

If 10m is quiet it is worth checking CB frequencies (11m) as a “band open” sign. Often CB can be busy when 10m is quiet due to lack of activity.  Thanks to Steve VE7SL for this good advice.

At night and in the quiet years it is an ideal band for local nets on FM or AM. At 1.7MHz wide it is big band so all modes can be supported.

See https://sites.google.com/site/g3xbmqrp3/hf/10m_op .

DXing with crystal sets

Yes, it is possible to hear a long way on a crystal set. The equipment needed can be extremely simple too.  What is needed are a good pair of ears and sensitive headphones.   My ears are getting old and if I can hear this DX then younger ears certainly can. I have found a low cost very high impedance crystal earpiece worked well. You may have better headphones?

Copying amateurs, most of whom use SSB, is more difficult. Remember, a simple crystal set is only able to envelope detect, although in the USA 75m AM signals are regularly copied at great range. Some SSB signals on 10m Es should be strong enough to envelope detect. Based on my tests, if stronger than 500uV to 1mV the signals should be copyable. Quite a few signals can be this strong.

See  https://sites.google.com/site/g3xbmqrp3/hf/crystalset .

Amateur Radio Weekly – Issue 64

Newsline Co-Founder, Editor Bill Pasternak, WA6ITF, SK
A well-known voice in the Amateur Radio news media has gone silent.
ARRL

Icom IC-7851 HF/50MHz Transceiver
With the design of the IC-7851, Icom’s engineers focused on a new Local Oscillator (LO) that drastically reduces the phase noise. As a result of this design, the purity of the LO achieves a Reciprocal Mixing Dynamic Range (RMDR) of 110dB.
Icom

ARRL June VHF Contest this weekend
For amateurs in the US and Canada to work as many stations in as many different 2 degrees x 1 degree Maidenhead grid squares as possible above 50 MHz.
ARRL

How to work a VHF contest
This is a brief introduction to operating during a VHF contest.
KØNR

[Video] June VHF Contest in action
QRP portable on top of Slide Mountain in the Catskills of New York.
K2FR

Monitoring FBI survielence aircraft with ADS-B
From reports on the internet John found out that FBI aircraft squawked with 4414 or 4415 codes, and used call signs like JENNA or JENA.
RTL-SDR.com

Summertime CBer
Strong Es on 11 meters usually heralds the possibility of 6m also opening via the same mode.
VE7SL

TV signals used to track aircraft as alternative to radar
Using special receivers, researchers said they were able to track up to 30 planes simultaneously flying at altitudes of up to 10,000ft (3km).
BBC

Dayton Hamvention – R.I.P.
The “laws of the market place” are taking care of the “Dayton as a hell-hole” problem.
With Varying Frequency

Semaphore + Morse Code + SSB + Twitter = Art
On Saturday, June 20 artist Philippe Druez ON1PHD will be performing at the Academy of Fine Arts, Ghent, Belgium with the iSemaphore installation using Chappe semaphore, Morse code and Twitter.
Southgate

Video

Tracking & receiving the LightSail cube satellite
Showing how to track the LightSail CubeSat on your own PC with free software.
YouTube

Video tour of a CubeSat satellite
AMSAT Fox-1C Engineering Model 6/6/2015
YouTube

Pye Telecom PF8

Some years ago I was professionally involved in the design of this innovative transceiver. I am sure I mentioned this on the blog not too long ago.

Some people managed to find rare examples on the secondhand market and converted them to 70cms use. They are hard to find as not that many were made.

See https://sites.google.com/site/g3xbmqrp3/vuhf/pf8 .

Plagued with noise in radio room, culprit? Battery (Smart) Chargers

I do not do much operating in my radio room in the house, most of my operations are done portable. But for some time now I have been plagued with some major noise to my rigs, the noise is about S9 or more at times and varies on certain frequencies and sometimes with odd sounds.

Not too long ago I had rebuilt my 24v battery pack for my PRC-104 with NiMh batteries, what I had found when the charger was working was the noise was atrocious, once battery was charged the noise would subside but I guess it was never totally gone. So one day when all of our power was down for a tree on the line I tested the radios with battery and found zero noise levels, none what so ever, so it lead me to start searching a bit deeper, looking at TV noise, routers etc, but still no luck nailing the problem.

So I continued to do a bit of more pulling of plugs and seeing what and where the noise could be coming from. I own many types of battery packs and chargers, batteries for radios, cameras and scanners, so I had to start one at a time. I leave the chargers always plugged in ready to go, so never really anticipated that this would be my issue. But I was very surprised when I found two of my chargers that were the problem.

The one charger was indeed my smart charger for my NiMh battery pack for my PRC-104.

 

The other charger that turned out to be an issue was a Duracell battery charger that I use for my camera batteries. It was amazing at how quiet things got once they were unplugged. The noise on my VX-1700 with these chargers plugged in and not being used would be a solid 9 and more, once I unplugged both of these units the noise dropped to a 3 and I could hear stations once again. I need to look at some of the other chargers in the house that are used for routers and other items in the house.

The NiMH charger when charging makes all bands useless when it is actually charging, the charger for my VX-1210 is the same, very loud noise levels emitted from these units.

So I am glad I did a bit of unplugging and checking and have found some of the issues that have plagued the home shack. Many of today’s electronics is just plain noisy and does emit all kinds of stray RF and noise.


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!

Have a ham radio product or service?
Consider advertising on our site.

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: