1
Shortwave Pirate Radio In North America And Around The World, And Other Signals That Go Bump In The Night
We seek to understand and document all radio transmissions, legal and otherwise, as part of the radio listening hobby. We do not encourage any radio operations contrary to regulations.
Always consult with the appropriate authorities if you have questions concerning what is permissible in your locale.
http://ka7oei.blogspot.com/2023/09/
KA7OEI’s conclusions:
“….The best HF weak-signal performance for the RX-888 (Mk2) will occur with the receiver configured for "High" gain mode, 0 dB attenuation and a gain setting of about 20dB. Having said this, you should always to the "antenna versus no antenna" test: If you see more than 6-10dB increase in the noise level at the quietest frequency, you probably have too much gain. Conversely, if you don't see/hear a difference, you probably need more gain - taking care in doing so.
For best HF performance of this - or any other wideband, direct-sampling HF SDR (RX-888, KiwiSDR, Red Pitaya, etc.) additional filtering is suggested - particularly the "shelving" filter described above.
In situations where the noise floor is very low (e.g. a nice, receive quiet location) many direct-sampling SDRs (RX-888, KiwiSDR, Red Pitaya) will likely need additional gain to "hear" the weaker signals - particularly on the higher HF bands. While some of these receivers offer onboard gain adjustment, the use of external high-performance amplification (along with filtering and careful adjustment of the devices' gain adjustments) will give improved absolute sensitivity while helping to preserve large-signal handling capability.
Because the RX-888 is a computer-connected device, there will be ingress of undesired signals from the computer and the '888's built-in circuitry. The use of external amplification - along with appropriate decoupling (e.g. common-mode chokes on the USB cable and connecting coaxial cables) can minimize the appearance of these signals…….”
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2
22 Meter Band HiFER Beacons / KEPR 13564.29 kHz 1332Z
« on: January 28, 2025, 1333 UTC »
Weak, fading in and out.
Rcvr: KiwiSDR, Northern VA, longwire antenna
Rcvr: KiwiSDR, Northern VA, longwire antenna
3
The RF Workbench / MPJA closing
« on: January 02, 2025, 1803 UTC »
I often buy electronic parts from Marlin P. Jones & Associates in Florida (www.mpja.com)
Lately I have noticed them closing out more and more of their inventory and offering significant discounts (currently at 20%) on other stock.
I checked with them and they confirmed they are planning on closing sometime in 2025. Sales have dropped, possibly due to hobbyists buying direct from China.
They join a growing list of companies that cater to the hobby and have shut down in the past few years, including All Electronics, Fair Radio, and Universal Radio.
Lately I have noticed them closing out more and more of their inventory and offering significant discounts (currently at 20%) on other stock.
I checked with them and they confirmed they are planning on closing sometime in 2025. Sales have dropped, possibly due to hobbyists buying direct from China.
They join a growing list of companies that cater to the hobby and have shut down in the past few years, including All Electronics, Fair Radio, and Universal Radio.
4
General Radio Discussion / WRC27
« on: August 09, 2024, 1139 UTC »
The FCC is asking for inputs on draft US positions for WRC27. The details are here:
https://docs.fcc.gov/public/attachments/DA-24-774A1.txt
Most of the items are satellite related, but this one is HF. (Note the mention of financial system low latency transmissions. That would be HFT…)
UNITED STATES OF AMERICA
DRAFT PRELIMINARY VIEWS ON WRC-27
AGENDA ITEM 1.9: to consider appropriate regulatory actions to update Appendix 26 to the Radio Regulations in support of aeronautical mobile (OR) high frequency modernization, in accordance with Resolution 41 (WRC‑23).
ISSUE:
The High Frequency (HF) band has been identified as an effective alternative to provide much needed integrated and interoperable Beyond-Line-of-Sight (BLOS) communications capabilities. HF is also a critical and affordable option for global broadcasting and amateur radio, and an alternative when other communications services are unavailable due to natural disasters or other national emergencies. Commercial financial institutions are exploring the use of HF long-distance delivery for financial users requiring low latency data. The challenge with meeting the growing requirement for modern HF is the need for the increased bandwidth allocations that would be required to achieve HF’s advantages while not impeding the legacy frequency needs of incumbent users, groups, or countries.
There are modern wide band HF (WBHF) technologies available that enable the flexibility to use wider channel bandwidths within advanced digital HF and enhanced applications that can support a shared environment while also maximizing spectrum efficiency. Current wideband technology and methodologies are available that automate the negotiating of the Radio Frequency (RF) environment while mitigating any harmful interference to users in, or adjacent to, a desired HF frequency range.
Appendix 26 of the ITU Radio Regulations limits Aeronautical Mobile (OR) to a maximum bandwidth of 2.8 kHz.
BACKGROUND:
WRC-23 through Resolution 411 (WRC-23) resolves to invite the Radiocommunication Sector to review Appendix 26 of the Radio Regulations and consider necessary changes, as appropriate, to Appendix 26, on the basis of studies without modifying the existing area allotments, and while taking into account that the current use of the narrowband systems shall remain unchanged and shall not be impacted nor precluded by the revision of Appendix 26.
The band 3500 – 4000 kHz is allocated to the Amateur Radio Service on a primary basis in Region 2, and is allocated in the 3500 – 3800 kHz range in Region 1 and the 3500 – 3900 kHz range in Region 3. This band is intensively used for Amateur Radio operations throughout Region 2, and that use is expected to increase.
U.S. VIEW:
The U.S. supports updating Appendix 26 of the Radio Regulations to allow for the use of wider channel bandwidth in the following bands allocated to AM(OR)S as long as sharing studies show the ability of HF wideband systems to ensure compatibility with existing AM(OR)S systems and with other incumbent services in the following bands, and adjacent allocations:
- 3025 – 3155 kHz
- 3900 – 3950 kHz (Region 1 only)
- 4700 – 4750 kHz
- 5680 – 5730 kHz
- 6685 – 6765 kHz
- 8965 – 9040 kHz
- 11175 – 11275 kHz
- 13200 – 13260 kHz
- 15010 – 15100 kHz
- 17970 – 18030 kHz
https://docs.fcc.gov/public/attachments/DA-24-774A1.txt
Most of the items are satellite related, but this one is HF. (Note the mention of financial system low latency transmissions. That would be HFT…)
UNITED STATES OF AMERICA
DRAFT PRELIMINARY VIEWS ON WRC-27
AGENDA ITEM 1.9: to consider appropriate regulatory actions to update Appendix 26 to the Radio Regulations in support of aeronautical mobile (OR) high frequency modernization, in accordance with Resolution 41 (WRC‑23).
ISSUE:
The High Frequency (HF) band has been identified as an effective alternative to provide much needed integrated and interoperable Beyond-Line-of-Sight (BLOS) communications capabilities. HF is also a critical and affordable option for global broadcasting and amateur radio, and an alternative when other communications services are unavailable due to natural disasters or other national emergencies. Commercial financial institutions are exploring the use of HF long-distance delivery for financial users requiring low latency data. The challenge with meeting the growing requirement for modern HF is the need for the increased bandwidth allocations that would be required to achieve HF’s advantages while not impeding the legacy frequency needs of incumbent users, groups, or countries.
There are modern wide band HF (WBHF) technologies available that enable the flexibility to use wider channel bandwidths within advanced digital HF and enhanced applications that can support a shared environment while also maximizing spectrum efficiency. Current wideband technology and methodologies are available that automate the negotiating of the Radio Frequency (RF) environment while mitigating any harmful interference to users in, or adjacent to, a desired HF frequency range.
Appendix 26 of the ITU Radio Regulations limits Aeronautical Mobile (OR) to a maximum bandwidth of 2.8 kHz.
BACKGROUND:
WRC-23 through Resolution 411 (WRC-23) resolves to invite the Radiocommunication Sector to review Appendix 26 of the Radio Regulations and consider necessary changes, as appropriate, to Appendix 26, on the basis of studies without modifying the existing area allotments, and while taking into account that the current use of the narrowband systems shall remain unchanged and shall not be impacted nor precluded by the revision of Appendix 26.
The band 3500 – 4000 kHz is allocated to the Amateur Radio Service on a primary basis in Region 2, and is allocated in the 3500 – 3800 kHz range in Region 1 and the 3500 – 3900 kHz range in Region 3. This band is intensively used for Amateur Radio operations throughout Region 2, and that use is expected to increase.
U.S. VIEW:
The U.S. supports updating Appendix 26 of the Radio Regulations to allow for the use of wider channel bandwidth in the following bands allocated to AM(OR)S as long as sharing studies show the ability of HF wideband systems to ensure compatibility with existing AM(OR)S systems and with other incumbent services in the following bands, and adjacent allocations:
- 3025 – 3155 kHz
- 3900 – 3950 kHz (Region 1 only)
- 4700 – 4750 kHz
- 5680 – 5730 kHz
- 6685 – 6765 kHz
- 8965 – 9040 kHz
- 11175 – 11275 kHz
- 13200 – 13260 kHz
- 15010 – 15100 kHz
- 17970 – 18030 kHz
5
Equipment / MFJ is closing down
« on: April 26, 2024, 1416 UTC »
MFJ is closing their manufacturing lines. This also includes their other brands (Ameritron, Cushcraft, HyGain, etc.).
I’ve suspected this because their owner is over 80 and it seems like more and more of their products are out of stock.
People like to criticize MFJ and it is true that they often have quality control problems, but they have had an impact on the hobby and some of their products (like the 259 Antenna Analyzer) have become legendary.
https://mailchi.mp/62e24f2ccc99/a-heavy-sad-heart?
I’ve suspected this because their owner is over 80 and it seems like more and more of their products are out of stock.
People like to criticize MFJ and it is true that they often have quality control problems, but they have had an impact on the hobby and some of their products (like the 259 Antenna Analyzer) have become legendary.
https://mailchi.mp/62e24f2ccc99/a-heavy-sad-heart?
6
VHF/UHF Logs, including satellites and radiosondes / UHF Tacsat/LOS/DAMA pub
« on: January 21, 2024, 1342 UTC »7
General Radio Discussion / WWFD stays full-time digital
« on: October 12, 2023, 2143 UTC »
I can occasionally hear WWFD on my truck radio. It sounds surprisingly good for an AM band broadcast station.
https://www.radioworld.com/columns-and-views/from-the-editor/am-digital-wwfd-concludes-its-test-phase
https://www.radioworld.com/columns-and-views/from-the-editor/am-digital-wwfd-concludes-its-test-phase
8
General Radio Discussion / Larry Vanhorn SK
« on: October 12, 2023, 1227 UTC »
Larry Vanhorn, long time Military Comm DXer, writer for Monitoring Times, and author of “The Milcom Files” books passed away in August.
https://forums.radioreference.com/threads/announcement-passing-of-larry-van-horn-n5fpw.464071/
https://forums.radioreference.com/threads/announcement-passing-of-larry-van-horn-n5fpw.464071/
9
General Radio Discussion / DK8OK?
« on: September 26, 2023, 1420 UTC »
What ever happened to DK8OK? For a while there were many papers and articles written by him but lately I haven’t seen anything. His web site (DK8OK.org) seems to have been captured by some bogus entity.
10
SDR - Software Defined Radio / SDR front end filtering and preamps
« on: September 07, 2023, 1240 UTC »http://ka7oei.blogspot.com/2023/09/
KA7OEI’s conclusions:
“….The best HF weak-signal performance for the RX-888 (Mk2) will occur with the receiver configured for "High" gain mode, 0 dB attenuation and a gain setting of about 20dB. Having said this, you should always to the "antenna versus no antenna" test: If you see more than 6-10dB increase in the noise level at the quietest frequency, you probably have too much gain. Conversely, if you don't see/hear a difference, you probably need more gain - taking care in doing so.
For best HF performance of this - or any other wideband, direct-sampling HF SDR (RX-888, KiwiSDR, Red Pitaya, etc.) additional filtering is suggested - particularly the "shelving" filter described above.
In situations where the noise floor is very low (e.g. a nice, receive quiet location) many direct-sampling SDRs (RX-888, KiwiSDR, Red Pitaya) will likely need additional gain to "hear" the weaker signals - particularly on the higher HF bands. While some of these receivers offer onboard gain adjustment, the use of external high-performance amplification (along with filtering and careful adjustment of the devices' gain adjustments) will give improved absolute sensitivity while helping to preserve large-signal handling capability.
Because the RX-888 is a computer-connected device, there will be ingress of undesired signals from the computer and the '888's built-in circuitry. The use of external amplification - along with appropriate decoupling (e.g. common-mode chokes on the USB cable and connecting coaxial cables) can minimize the appearance of these signals…….”
11
General Radio Discussion / HF Traders
« on: August 13, 2023, 1453 UTC »
This epub contains a number of news about applications for FCC STAs. Most of the issues have an article of some sort about HFT stations. It is free, but you do have to provide your email address.
https://www.experimentalradio.news/
https://www.experimentalradio.news/
12
General Radio Discussion / Long Wave STA
« on: August 13, 2023, 1433 UTC »
From Experimental Radio News, issue 8:
(https://www.experimentalradio.news/experimental-radio-news-8/)
Longwave for remote sensing
Lunasonde was issued Special Temporary Authorization WV9XBO for experiments at 119-121 kHz, as it develops an Earth-sensing constellation to detect ground resources.
“Lunasonde’s ability to look 15,000 times deeper than current satellites and sensors is the next frontier in resource exploration," the company said. “Our small satellite can locate groundwater, mineral deposits, and other geological resources up to two kilometers underground. Our data is collected in three minutes and provides a true 3D map of the earth's subsurface."
For the low-frequency STA, “The proposed testing is necessary to increase the technology readiness level of the Lunasonde LF transceiver. A 100-foot structure located in Tucson, AZ will transmit in the requested frequency band.
“During a test mission, one uncrewed high-altitude balloon will carry one LF receiver system approximately 60,000-100,000 feet above ground level over the transmission structure. Transmitted signals that reflect from the Earth’s surface would be received by the free-floating balloon receiver system. ...
“The system is equipped with a redundant cut-down device, a radar reflector, and an ADS-B transponder… The balloon is returned to the ground either when it reaches maximum altitude (approximately 100,000-130,000 ft) or when the cutdown is commanded, at which point a parachute is used to safely return the payload to the ground. In either scenario, Lunasonde will retrieve the balloon and equipment.”
‘No expectations’ for future approval
“Lunasonde, Inc. shall have no expectations that future requests for operational use of this transceiver from low earth orbit using the 119-121 kHz band will be approved, and Lunasonde, Inc. should ensure that any future operational use of this equipment be conducted in appropriately allocated frequency bands,” the FCC told the company.
(https://www.experimentalradio.news/experimental-radio-news-8/)
Longwave for remote sensing
Lunasonde was issued Special Temporary Authorization WV9XBO for experiments at 119-121 kHz, as it develops an Earth-sensing constellation to detect ground resources.
“Lunasonde’s ability to look 15,000 times deeper than current satellites and sensors is the next frontier in resource exploration," the company said. “Our small satellite can locate groundwater, mineral deposits, and other geological resources up to two kilometers underground. Our data is collected in three minutes and provides a true 3D map of the earth's subsurface."
For the low-frequency STA, “The proposed testing is necessary to increase the technology readiness level of the Lunasonde LF transceiver. A 100-foot structure located in Tucson, AZ will transmit in the requested frequency band.
“During a test mission, one uncrewed high-altitude balloon will carry one LF receiver system approximately 60,000-100,000 feet above ground level over the transmission structure. Transmitted signals that reflect from the Earth’s surface would be received by the free-floating balloon receiver system. ...
“The system is equipped with a redundant cut-down device, a radar reflector, and an ADS-B transponder… The balloon is returned to the ground either when it reaches maximum altitude (approximately 100,000-130,000 ft) or when the cutdown is commanded, at which point a parachute is used to safely return the payload to the ground. In either scenario, Lunasonde will retrieve the balloon and equipment.”
‘No expectations’ for future approval
“Lunasonde, Inc. shall have no expectations that future requests for operational use of this transceiver from low earth orbit using the 119-121 kHz band will be approved, and Lunasonde, Inc. should ensure that any future operational use of this equipment be conducted in appropriately allocated frequency bands,” the FCC told the company.
13
The RF Workbench / All Electronics going out of business
« on: June 19, 2023, 1238 UTC »
All Electronics, a vendor of electronic parts, is closing in August. They were a source of some hard to find electronic parts (like old school high voltage mica transmitting capacitors).
www.allelectronics.com
www.allelectronics.com
14
The RF Workbench / Ferrites and Inductors for EMI Control
« on: June 01, 2023, 1732 UTC »
This is a good basic article on choosing ferrites and inductors for EM noise suppression. It discusses choices, best practices, and why your filters may be ineffective.
https://digital.incompliancemag.com/issue/june-2023/inductors-and-ferrites-for-use-in-emc/
https://digital.incompliancemag.com/issue/june-2023/inductors-and-ferrites-for-use-in-emc/
15
Equipment / State of HF transceiver art
« on: May 25, 2023, 1120 UTC »
This is from the 2023 CTU, and discusses the performance of current HF transceiver offerings. Most of the discussion is on receiver performance.
Note that it says 60,000 Icom IC7300 radios have been sold. This is surely the most popular HF radio ever. I have heard anecdotal stories of SWL’s buying them just to use as a receiver.
https://www.contestuniversity.com/wp-content/uploads/2023/05/Transceiver-Performance-Selection-of-a-Radio-2023.pdf
Note that it says 60,000 Icom IC7300 radios have been sold. This is surely the most popular HF radio ever. I have heard anecdotal stories of SWL’s buying them just to use as a receiver.
https://www.contestuniversity.com/wp-content/uploads/2023/05/Transceiver-Performance-Selection-of-a-Radio-2023.pdf
