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W1VT

Joined: Sat, Apr 4th 1998, 00:00 Roles: N/A Moderates: N/A

Latest Topics

Topic Created Posts Views Last Activity
QST Downloads Feb 19th 2016, 16:34 3 4,767 on 19/3/18
March 2016 QST Compact Multiband Dipole Feb 19th 2016, 15:23 1 2,853 on 19/2/16
Antenna analyzer vs feedline type Sep 21st 2012, 14:37 1 4,514 on 21/9/12
USB to Serial Port problems--Prolific Drivers Aug 3rd 2012, 18:27 2 5,353 on 26/12/15
Italian Phishing emails! Dec 13th 2011, 14:20 1 4,110 on 13/12/11
John K0GMO needs help designing SS Amp Nov 17th 2011, 15:53 1 4,054 on 17/11/11
1 Farad Capacitor to Eliminate Headlight Flicker? Oct 19th 2011, 13:14 4 5,911 on 9/11/11
History of Relay Rack Dimensions? Oct 17th 2011, 12:58 2 4,144 on 25/10/11
Miswired Selsyn Oct 13th 2011, 17:51 1 4,263 on 13/10/11
Stealth Antenna wire Sep 12th 2011, 12:51 2 4,840 on 13/9/11

Latest Posts

Topic Author Posted On
Inverted V Length Controversy. W9BOQ 3 days, 22 hours ago
There are at least six significant factors.
Insulation
Height above ground
Type of ground (conductivity and dielectric constant)
Other antennas
Angle of the Vee
Interaction with the coax shield with/without a balun

With this many variables, I suggest computer modeling or cut and try.

I have two dozen antennas and really good ground, so my yard is hardly representative of the "typical" ham station.
I've been grinding up leaves all winter to make compost to add even more organic matter to my soil.

Zak Lau W1VT
ARRL Senior Lab Engineer
80 Meter Trapped Dipole N8JLM 4 days, 5 hours ago
https://forums.qrz.com/index.php?threads/trap-antenna-harmonics.539832/
question about interference on 70 cm band AB3FN 6 days, 3 hours ago
https://www.govinfo.gov/content/pkg/CFR-2010-title47-vol1/pdf/CFR-2010-title47-vol1-part18.pdf
Part 18 does not allow ISM users to interfere with authorized radio services.

That is also true for Part 15 unlicensed devices.

https://www.fcc.gov/wireless/bureau-divisions/mobility-division/wireless-medical-telemetry-service-wmts
The Wireless Medical Telemetry Service (WMTS) is in the 608 – 614, 1395 – 1400, and 1427 – 1432 MHz range. WMTS spectrum is used for remote monitoring of a patient’s health. Wireless medical telemetry systems include devices to measure patients' vital signs and other important health parameters (e.g., pulse and respiration rates) and devices that transport the data via a radio link to a remote location, such as a nurses' station, equipped with a specialized radio receiver. For example, wireless cardiac monitors are often used to monitor patients following surgery.

Similar services include the Medical Device Radiocommunications Service (MedRadio).

Prior to establishing the Wireless Medical Telemetry Service (WMTS), medical telemetry devices operated on an unlicensed basis on vacant television channels 7-13 (174-216 MHz) and 14-46 (470-668 MHz) or on a licensed, but secondary basis to private land mobile devices in the 450-470 MHz band. This meant that wireless telemetry devices had to accept interference from the television broadcasters and private land mobile licensees.

Concerns over additional interference to medical telemetry devices became a greater issue as the transition from analog to digital television began. To help alleviate additional interference to wireless medical telemetry devices, the FCC took action to establish the Wireless Medical Telemetry Service (WMTS) in 2002 by allocating 14 MHz of spectrum for wireless medical telemetry.
Sheet Metal Fabricator for HAM Projects WA2FTV 1 week, 3 days ago
In 2012 we started using a new article archive by PageSuite and stopped linking PDFs to the old article archive. I just heard that the guy who used to do that has been retired from his last job for over a year.

The new archive allows you to view the entire issue of QST and do full text searches.
Which Forum for discussing ARRL policy? W5INC 1 week, 3 days ago
No, people can still discuss policy if they wish right here. I think it is helpful to that this thread exists. W5INC has made many posts on QRZ.com.

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