Tag Archives: Dan Srebnick

Dan seeks a comprehensive travel radio

Many thanks to SWLing Post contributor, Dan Srebnick, who writes:

Here’s a question to put to your blog readers. I’m looking for a compact portable receiver for travel purposes.

It must have AM, FM and shortwave coverage. It should support SSB and RDS. Synchronous AM is a plus, as is FM band coverage starting at 76 MHz (trip to Japan in the near future). Accurate digital readout is a must. But most importantly, MP3 and or wav recording at 48k should be supported. This last point seems to be a showstopper.

But, I’ll be in Brazil, Uruguay and Argentina soon and hope to capture some hard to hear signals. So, any ideas would be most appreciated.

Digitech AR-1780 (left) and XHDATA D-808 (right)

The XHDATA D-808 should fit the bill with two exceptions: synchronous detection and audio recording. The very similar Digitech AR-1780 should as well, although I’m not certain you can switch it to Japan FM frequencies (I bet there’s a hack to do it, although I’ve never tried).

As you suspect, built-in recording is certainly the feature that’s most difficult to find in a portable shortwave radio. The only shortwave receiver I’ve tested recently that has decent built-in recording is the Audiomax SRW-710S (a.k.a. Tivdio V-115). However, it lacks many of the other features you noted and isn’t on par with the D-808 in terms of receiver (it is quite cheap though). I’m not sure I’d rely on it for extended travels.

In your shoes, I might combine the XHDATA D-808 and the Zoom H1n to achieve all of your goals. True, it’s not all-in-one, but it should perform well and the H1n would allow you to do other types of field recording.

Update: One more thought… Although this isn’t a traditional portable radio, you might also consider grabbing the new AirSpy HF+ Discovery SDR and pairing it with a tablet or laptop. It’s a phenomenal receiver and ticks all of the boxes above.

Post Readers: Can you think of other options for Dan? Has another recording shortwave radio hit the market?  What radio or kit do you use for travel and field recordings?  Please comment!

Spread the radio love

WMR QSL card surprises Dan

May thanks to SWLing Post contributor, Dan Srebnick, who writes:

Unexpected SWBC QSL in the mail today [see above], the first in years.  World Music Radio 5815 kHz (7 kw) for a May 2004 report! Interestingly, mailed from Andorra where the EDXC meeting was just held.

Wow! A 5,588 day turn-around! As they say, “better late than never!” Thank you for sharing, Dan.

Spread the radio love

New Raspberry Pi 4: Faster CPU, Dual Monitors, Gigabit Ethernet and up to 4 GB of RAM

Many thanks to SWLing Post contributor, Dan Srebnick, who notes that the Raspberry Pi 4 mini computer was unveiled this morning by the Raspberry Pi Foundation.

This model has a number of upgrades we’ve all been waiting for:

I love the Raspberry Pi and own a number of models that I’ve employed in various projects. For example:

What excites me most about the Raspberry Pi 4 is the improved processor speed and larger allotment of RAM (up to 4 GB). This could make the Pi a more effective stand-alone or portable SDR station. The dual monitor capability could also be a big bonus. And, of course, GigaBit ethernet speeds will help make the Pi a better/faster connected device.

When the Raspberry Pi 3B+ was introduced last year, I hesitated one day and had to wait weeks for the second shipment. Not this time! I purchased two 4GB units (in two different shipments as most suppliers have a maximum of one per customer) and hope to receive them by mid-July.

If you’re interested in pre-ordering the Raspberry Pi 4, check out the Raspberry Pi Foundation website for recommended resellers.

Do you plan to grab a Pi 4? Would you like to share a recent project with us? Please comment!

Spread the radio love

Radio deal: Refurbished Whistler scanners on sale

Many thanks to SWLing Post contributor, Dan Srebnick (K2DLS), who notes that Whistler currently has a selection of refurbished scanners on sale with a manufacturer’s warranty including the new TRX-1 handheld:

Click here to view the sale at Whistler.

These are great prices! Thank for the tip, Dan!

Spread the radio love

Dan shares solar eclipse spectrum files

(Source: The K2DLS blog)

Solar Eclipse Data Collection Project

Between 1600 – 2015 UTC on August 21, 2017, as the solar eclipse swept across the nation, I captured much of the lower 2 MHz of the radio frequency spectrum.  I used a Microtelecom Perseus SDR, a 130? inverted L with four radials, and lots of disk space.  In doing so, I have created a permanent record of this portion of the RF spectrum during the solar eclipse.

I am making the spectrum capture files available for your analysis and research.  Each file contains a 5 minute segment.  If you download a group of files, they will play in succession.

You can use the demo version of the Perseus software or any other software that can read the Perseus data, such as Linrad or HDSDR.  You cannot use just an audio player to play the files, even though they have .wav extentions.

Should you perform any analysis or otherwise make use of the files, I’d like to hear from you in the comments below.

Special thanks to Jav, K4JH, for donating the bandwidth for this effort.

Many thanks, Dan and Jav for making these files available for download! Someday, if I can find the bandwidth and space to upload them, I’ll also share the spectrum recordings I made.

Click here to check out K2DLS’ blog.

Spread the radio love

Solar Eclipse 2017: In the path of totality

A portion of the PARI campus

Tomorrow, we will be experiencing a total solar eclipse here in the mountains of western North Carolina.

Instead of enjoying the eclipse at home, I will be volunteering as a docent at the Pisgah Astronomical Research Institute in Rosman, North Carolina. Post readers might recall PARI as it was the location of our 2015 PARI DXpedition.

One of PARI’s 26 meter radio telescopes.

PARI is expecting at least 1,000 visitors tomorrow, from a number of countries. Many are scientists, astronomers, and guests who want to be in the path of totality.

On the PARI campus, we will be in totality for about 1 minutes, 47 seconds.

What makes the event truly special for PARI is that this is the first time in history a world-class radio astronomy observatory has been in the path of totality. To say the PARI astronomers are excited is simply an understatement. All four of PARI’s telescopes will be trained on our local star and gathering copious amounts of data.

If you don’t live in the path of the Eclipse, I invite you to check out PARI’s YouTube channel where they will host a live stream:

Click here to watch on YouTube.

Gathering spectrum

I will also be gathering data of my own during the event.

I will remotely record the entire mediumwave (AM broadcast) band several hours before, during and after the eclipse. I will also set up a separate SDR to record either the 31/30 meter bands and my buddy, Vlado (N3CZ) is kindly using his SDRplay RSP1 to record from 6 MHz – 8 MHz.

What do I expect to see/hear in the spectrum recordings? Certainly a drop in noise. If I’m lucky, I also hope to hear some DX anomalies–hopefully a signal or two that I wouldn’t normally here in the middle of a summer day.

I don’t expect any dramatic results (though I would love to be proven otherwise!) since the ionosphere takes time to change states. My buddy Mike (K8RAT) likens it to an oven: it takes time for it to heat up to the desired temperature, and it takes time for it to cool down as well. I’m not so sure the shadow of the moon, which moves at a good clip, will be persistent enough to change the state of the ionosphere in any meaningful way.

If it does, I’ll be there to record it!

There are many other radio related experiments happening during the solar eclipse. A notable one that you can even help with is the 2017 Ham Radio Eclipse Experiment.

SWLing Post contributor, Dan Srebnick also suggests a few stations you might try catching on the AM broadcast band. Dan notes:

Something to do during the solar eclipse on Monday. There are 13 clear channel AM stations along the path of totality. Give a listen for them:
[LIST OF AM CLEAR CHANNEL STATIONS]
kHz CALL Location Eclipse UTC
—— ——- —————- ————–
650 WSM Nashville, TN 18:28
670 KBOI Boise, ID 17:27
750 WSB Atlanta, GA 18:36
840 WHAS Louisville, KY 18:27
880 KRVN Lexington, NE 17:57
1030 KTWO Casper, WY 17:43
1040 WHO DesMoines, IA 18:08
1110 KFAB Omaha, NE 18:04
1110 WBT Charlotte, NC 18:41
1120 KPNW Eugene, OR 17:17
1120 KMOX St. Louis, MO 18:18
1190 KEX Portland, OR 17:19
1510 WLAC Nashville, TN 18:28

Kudos to Bob WB4APR (of APRS fame) for producing this list.

Post readers: Will you be in the path of totality or do you plan to enjoy a partial eclipse? Have you ever experienced a total solar eclipse?  What are your plans if any? Please comment!

Spread the radio love

Dan’s take on ADS-B with the Raspberry Pi B model

Many thanks to SWLing Post contributor, Dan Srebnick (K2DLS), who recently posted a detailed overview of his ADS-B installation on his blog:

Monitoring NextGen ATC (on the cheap!)

A key component of next generation air traffic control is Automatic Dependent Surveillance – Broadcast (ADS-B). The current FAA mandate is for all included aircraft to output ADB-B transmissions no later than January 1, 2020. But you don’t have to wait to receive and map ADS-B. There is a lot of air traffic to be seen.

[…]I decided to use a spare older RTL-SDR stick based on the RTL2832U and R820T chips. This USB device comes with a small antenna that I hoped would be good enough to get me started. It is not in any way optimized for the 1090 MHz signals that are used by ADS-B and is roughly 19 parts per million (ppm) off frequency. It cost a bit over $10 at a hamfest a couple of years ago. The designs have improved since the early models were offered. Newer models include a TCXO (thermally compensated crystal oscillator) for stability and accuracy.

I needed software to take signals from the RTL-SDR stick and plot them on a map. That software is “dump1090”, originally written by Salvatore Sanfilippo. I added an install stanza to the Makefile, along with a systemd service file, for a smooth system install. I also needed to install the RTL-SDR USB drivers. The complete installation runs “headless”, meaning no monitor, keyboard or mouse need be connected. Remote management can be done via ssh.[…]

Continue reading on Dan’s blog…

This is fantastic, Dan! Thank you for taking the time to share all of the code snippets you needed to do the installation on the Raspberry Pi B as well. Post Readers: if you have an older Raspberry Pi and RTL-SDR sitting on a shelf, use Dan’s guidance to turn them into an ADS-B feeder!

Click here to read my ADS-B feeder tutorial based on the Raspberry Pi 3.

Spread the radio love