Here is the SWR plot for it when used for transmitting:
I confirmed this plot with an antenna analyzer after it was mounted at 65 ft. high and it was very close. The antenna is about 130 feet long and is supported on both ends as well as the center.
The Antenna
Get lots of questions about the antenna. Here is a link to it at Palomar Engineers. It is a terrific antenna and is also great for transmitting on the ham bands.
Here is the SWR plot for it when used for transmitting:
I confirmed this plot with an antenna analyzer after it was mounted at 65 ft. high and it was very close. The antenna is about 130 feet long and is supported on both ends as well as the center.
Here is the SWR plot for it when used for transmitting:
I confirmed this plot with an antenna analyzer after it was mounted at 65 ft. high and it was very close. The antenna is about 130 feet long and is supported on both ends as well as the center.
Lonely Guys Net - 75 meter
One of the more interesting ham radio nets is the Lonely Guys Net on 3875 kHz on Saturday mornings at 8:00am ET. They usually have a large number of check-ins and an interesting topic of the day that gets discussed.
The video below does not do the content of the net justice but it does sound great on this old Hallicrafters.
The video below does not do the content of the net justice but it does sound great on this old Hallicrafters.
Pirate Radio Activity
Check out the 6900-6970 kHz range for potential pirate radio activity. Many stations broadcast in USB mode but some are AM. Programming and times are widely variable as is signal strength. Weekends and holidays are especially active.
For more information, check out the posts on HF Underground as members will often post what they are hearing. You can also join the HF Underground Chat to get information in real time as other listeners hear a new station.
For more information, check out the posts on HF Underground as members will often post what they are hearing. You can also join the HF Underground Chat to get information in real time as other listeners hear a new station.
Quarter Wave Notch Filter for 41 Meters
To help solve the 41 meter (7300-7500 kHz) shortwave transmitter overload a quarter wave stub has been inserted to help attenuate just that part of the band. More info here.
The filter is wide so there is affects frequencies +/- 10% of the design frequency. The further away from the design frequency, the less the attenuation.
The filter has improved the overload issue and is only a minor inconvenience on the 40 meter ham band.
The filter is wide so there is affects frequencies +/- 10% of the design frequency. The further away from the design frequency, the less the attenuation.
The filter has improved the overload issue and is only a minor inconvenience on the 40 meter ham band.
41 Meter Shortwave Transmitter Overload
The receiver's location is very good and the receiver is getting some overload from a couple of high powered shortwave broadcasters in the 41 meter band (7300-7300 kHz). This will cause distortion across the whole 0-32 MHz spectrum when the signal gets to 60 dB over S9. A 20 dB attenuator has inserted as a brute force workaround. A better solution will be coming soon.
ΣSDR - CT/MA Border, Northeast USA
ΣSDR - CT/MA Border, Northeast USA
http://sigmasdr.ddns.net:8073
This online SDR is a KiwiSDR that allows four online users to share the same receiver. It covers 0 to 32 MHz with the following modes: AM, CW, LSB/USB, FM and extensions that allow you to decode SSTV, CW, FSK, and more.
The antenna is an off center fed dipole at about 65 ft above the ground. The elevation is approximate 800 feet above sea level and the terrain slopes off a couple hundred feet toward a large reservoir. Reception is excellent on almost all bands.
If you use this receiver, please sign in (top right of the SDR screen). It will also save your last settings for your next visit. Please be considerate if you are not actively listening and close your browser window so some one else can use one of the four slots.
I welcome emails from anyone who uses this receiver. It is always interesting to know who uses it and what they listen to.
http://sigmasdr.ddns.net:8073
This online SDR is a KiwiSDR that allows four online users to share the same receiver. It covers 0 to 32 MHz with the following modes: AM, CW, LSB/USB, FM and extensions that allow you to decode SSTV, CW, FSK, and more.
The antenna is an off center fed dipole at about 65 ft above the ground. The elevation is approximate 800 feet above sea level and the terrain slopes off a couple hundred feet toward a large reservoir. Reception is excellent on almost all bands.
If you use this receiver, please sign in (top right of the SDR screen). It will also save your last settings for your next visit. Please be considerate if you are not actively listening and close your browser window so some one else can use one of the four slots.
I welcome emails from anyone who uses this receiver. It is always interesting to know who uses it and what they listen to.
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