HF EmComm Sr Antenna
$219.00
End-fed 10-160M EmComm antenna
MODEL: HF JPole Sr
10-160 meter end-fed 60-foot long HF Antenna that enables you to use a tuner to achieve a near perfect SWR, with limited efficiency while using a tuner on 160 meters.
Specifications
- Frequency Coverage: 1.8-29.7 MHz (160-10 Meters)
- Peak Power: 250 PEP SSB, 125 CW, or 25 watts for digital modes. NOTE – The MIL-STD-188 M110a digital communications mode is rated at bursts of 100 watts digital for up to 1 minute using the MIL-STD Data Modem Terminal (MS-DMT) and Automated Message Terminal (AMT) software applications.
- Length: 60 Feet
- Weight: 1 pound
- Configuration: End-fed antenna configurable as Sloped or Horizontal
- Connector: UHF type SO-239
Analysis
| 60 Foot element | |
| Band | SWR |
| 10 Meters | 1.61 |
| 12 Meters | 2.43 |
| 15 Meters | 1.75 |
| 17 Meters | 1.52 |
| 20 Meters | 2.20 |
| 40 Meters | 2.67 |
| 80 Meters | 2.08 |
Deployment
Run the antenna as a sloped system for good NVIS and DX results, or a flat top for good NVIS results. We test the antennas at 6 feet, however higher placement will enhance DX results while lower placement will enhance NVIS.
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Specifications, prices, and descriptions are subject to change without notice.
Reviews
| 5 star | 100% | |
| 4 star | 0% | |
| 3 star | 0% | |
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| 1 star | 0% |
| Weight | 80 oz |
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| Dimensions | 12 × 9 × 5 in |
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| mpn | |
| product type | Base HF VHF UHF Antennas, EmComm Antenna, End Fed Dipole Antennas, Marine and land-based VHF UHF HF Mobile Antennas, Military Aviation Commercial Antenna, Portable HF VHF UHF Antennas, VHF UHF HF Antennas |
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| SKU | |
| VHF UHF HF Antenna type | HF Base Stealth Antenna Systems, HF Dipole Antennas, HF Emergency EmComm Antennas, HF Military MilCom Antennas, HF Portable Stealth Antennas |
Q & A
Yes. Please see the manual for rope use here https://www.alphaantenna.com/manuals/JPole_Sr_v2.9_by_Alpha_Antenna.pdf
You may need one mainly if you are experiencing common mode current, especially after you have placed ferrite beads on the devices power cord that is experiencing common mode current. Note - Sometimes resolution is made by simply moving the devices power cord to a different circuit. If, for example, you still hear your own transmission coming from a pair of speakers then we recommend reading the following article: "The Need (or not) for Antenna Baluns or Chokes": https://www.alphaantenna.com/community/hints-and-kinks/news/the-need-for-antenna-baluns-ensuring-efficient-signal-transmission/
To enhance NVIS, mount the element lower than 8 feet in a horizontal configuration. For better DX, mount the element in the clear and sloped into the direction you want to launch your signal. For example, with one end at 6 feet and the other at 30 feet (Note that higher typically results in more DX). Again, the slope helps determine the angle and direction that your signal is launched.
Previous design: In July 2023 Alpha Antenna changed what was their 5:1 UnUn with a single element as the radiator and one element as the counterpoise.
Current design: The result of this change is an end fed fan dipole arrangement fed to a modified 5 to 1 UnUn.
What changed?: While monitoring with both RigExert and AIM analyzers, physical changes were made in real-time to the inductor with the new configuration of the two wire elements attached. Those analyzers simultaneously monitored all of the bands, while physical changes were made to the inductor. We stopped making changes once the best values were presented. During this process, we found that the shorter leg of the two wire elements also had to be modified to present excellent results. The value of the new UnUn has not been tested, nor do we care to test it, we simply enjoy the results of a finely tuned system.
Comments: To construct the UNUN, specialized tools were built on our 3-D printers. Without these tools, construction of the new UnUn in a production environment was nearly impossible. Fortunately, we use Fusion 360, which made designing the tools possible.
The JPole (Jr & Sr) are derived from a fan dipole’s design, which simply enables RF to select the element(s) with the path of least resistance for the resonance required to provide acceptable SWRs. The second shorter element is an active element that that is attached to the longer element in a zip cord configuration. This enables the end fed JPole antenna to have access to 3 electrical lengths of wire. These lengths are: 1) The shortest element, 2) the longest element, 3) and an even longer combined length of 1 and 2. Then an inductor matches the impedance at the point where your 50-ohm coax attaches to the match. Operationally, the JPole Sr is designed with the optimum lengths of elements, and the 34-foot JPole Jr was designed for those who do not have the room to deploy a 60-foot JPole Sr antenna.
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Unique design with the counterpoise routed along the radiating wire. I rarely use the antenna tuner my yt-991a has, good > 2.0 match almost across the spectrum with some deviation on 40 meters (2.5 SWR)
Outstanding antenna. It exceeded my expectation especially since I have the feedpoint at a less than ideal height. I am very pleased with it.
Needed a stealth setup so as not to upset my better half. Saw a great review on YouTube by HamJazz and he was spot on!
Finally got the antenna installed today and it meets my expectations. Installed on top of a 6 foot wood fence. Made contacts on East Coast right off the bat from central Illinois. Tried to work California but there was to much QRM. Have not doubt I will cover all of North America and possibly beyond. Thanks Alpha.