This weekend LF and MF time!

After much time doing only microwaves activities, I listened the encourage words from Luis EA5DOM, to try to receive LF and MF . Luis is active in 136kHz and 477kHz in TRX and uses Opera, WSPR and have a SpectrumLab grabber.

Icom IC-R9000 and IC-781 used

Icom IC-R9000 and IC-781 used

On the right the PA0RDT mini-whip antenna

On the right the PA0RDT mini-whip antenna

I build a PA0RDT mini-whip antenna and erected it 6 meters over the floor, as receivers I used my Icom IC-R9000 for 136kHz and the  Icom IC-781 for 477kHz. I tested Opera, WSPR and Argo for QRSS.

WSPR-2 stations in 477kHz

WSPR-2 stations in 477kHz

WSPR-15 signals in 136kHz

WSPR-15 signals in 136kHz

Opera32 stations in 136kHz

Opera32 stations in 136kHz

G3XDV in slow CW QRSS/60 in 136kHz

G3XDV in slow CW QRSS/60 in 136kHz

DK7FC in DFCW in 136kHZ

DK7FC in DFCW in 136kHZ

The most common modes are OPERA32 (32 mins period), wspr15 ( 15 mins period) in 136kHz, and OPERA-8 (8 mins period) WSPR-2 (2 mins period) in 477kHz. The OPERA and WSPR uploads to Internet the receptions as spots and is possible check online the results and distance. This is feature is very nice to compare results with another stations.

wsprnet.org map with the WSPR-2 stations received in 136kHz

wsprnet.org map with the WSPR-2 stations received in 136kHz

pskreporter.info maps with the OPERA-32 stations received at 136kHz

pskreporter.info maps with the OPERA-32 stations received at 136kHz

I’m really surprised for the good results and for the nice signals that can be received in this low frequencies with a small antenna. I know that this band some times not are easy for the local QRM/QRN generated by switched power supplies, motors, etc.. but with not much effort is possible get some setup to receive this bands.

I encourage that you try to receive this bands. A good point to start is the 477kHz band. It can be received easy using a base HF transceiver and antenna.

Cheap and easy to build 1296MHz EME feedhorn for offset dishes

Recently I build a circular polarization feedhorn to try to do EME in 1296 MHz. The hint was that it have very easy to build and cheap. I was looking some designs based in ual mode septum designs from N2UO and RA3AQ but they not are easy to build for me. My idea has been use fireplace pipe and a dielectric depolarizer.

1296 Dual mode feedhorn

1296 Dual mode feedhorn

To build the feehorn I have used fireplace inox pipe of 150mm and a galvanized reduction from 250 to 150mm. The dielectric depolarizer is a piece of Rogers Duriod 5880. To try to minimize the number of sma connectors, I used a small piece of Suhner .141 as a probe that will connect directly to the LNA saver switch.

Building the RX probe

Building the RX probe

RX port probe

RX port probe

Feedhorn inside

Feedhorn inside

In the TX port I used a standard N connector. I measured the RL in the lab, but have to measure the RL in the dish for this reason the bottom plate not is soldered yet, it is glued using metalic tape, until the RL is adjusted on the dish.

Measuring return loss

Measuring return loss

Feedhon on the dish

Feedhon on the dish

Detected meteor that has crossed tonight over Catalonia

Tonight, I was recording the Graves radar frequency (143.050 MHZ) to see I can detect the 2014 RC asteroid without success. But over a nice meteor has crossed Catalonia at the 04:56:50 UTC  and has ben detected 🙂

bolid

Meteor detected

The signal not is specially strong, because the target was very near from me. Using the Graves radar is more easy see meteors that are impacting from more remote locations of France or Italy

Other meteors can be observer before and after the target

Graves radar to UTC correlation

The Graves radar uses a multibeam antenna system that is switched every 0.8 seconds. When a meteor is detected and prints a large trace, is easy to see the beam switching after the meteor.

Graves beam switching

Graves beam switching

As the Graves radar system uses the transmitter and receiver in different geographic locations, is easy to think that they are synchronized the the UTC.

To check if it is true Miguel EA4EOZ and me are doing stereo recordings stereo of the Graves radar in one channel and a 1PPS signal from a GPS receiver in the other channel. And efectively they are  locked to the UTC 🙂

Graves radar 1PPS correlation

Graves radar 1PPS correlation

The coincidences to UTC are in the second 0,4,8,12,16,etc.. of every minute.

Some usefull info can be readed on the PE1ITR website.

PE1ITR, Greaves beam diagram

PE1ITR, Greaves beam diagram

More confirmations of my ISEEE-3 detection

Space Collage:

According to our team “The frequency offset is ~18025 Hz on Spectravue, so it looks likely. He’s tuned to XB, so just seeing the very tip of the PM carrier.”

http://spacecollege.org/isee3/detecting-isee-3-with-a-8-foot-dish.html

Phil Karn KA9Q

“I calculate a C/N0 of -2.5 dB-Hz for you, depending on mod index. Seem right? That’s weak!”

https://twitter.com/ka9q/status/475739296708567041

Confirmation of my ISEE-3 detection from James Miller G3RUH

Dear Iban,

Thank you for the timestamp, qth etc, and the info about the Spectravue
header format.

I examined the file anyway and worked out that a “stereo” signal was I and Q,
16-bits each, LSB first.

I confirm the signal as you found.  I averaged small and large numbers of
FFTs.  This showed that the signal strength varied, between approximately
11 to 16 dB-Hz.  The spacecraft is spinning at about 3 rpm, so this may be
the reason.

Attached is a typical plot from my my own software.  This is not the strongest
signal display; the largest I found was a signal = -45.7 dB over the
noisefloor = -53.8 dB, or SNR = 8.1 dB.

With a bin bandwidth of 0.124 Hz, this equates to a CNR of 16.4 dB-Hz.

Congratulations!

73 de James G3RUH

ISEE-3 signal processed by G3RUH

ISEE-3 signal processed by G3RUH