May 6, 2021 Club Meeting

Thursday, May 6, 2021 at 7:00 PM Via Zoom. Login sent via email or upon request.

Program: TBA

The program for May has not been firmed up at the time of newsletter publication.

Announced in the May 2021 issue of The Repeater.

Meeting Notes

From the June 2021 issue of The Repeater.

RVARC Meeting Minutes, 2021-05-06

7:00 PM Meeting started on Zoom

About 10 people were in attendance.

Allan, K7GT, had questions for Tom, N5EG, about last meeting’s smith chart program.

7:02 PM Scott, AJ7S, mentioned recently working around 280 contacts on JT8 from over 32 states with his attic mounted dipole and mag loop. Noise levels were surprisingly low.

7:08 PM Treasurer’s report. Mike, WB6FFC, was reported to have filed the IRS Form 990N for this year, and the bank balance increased $45 from membership dues paid.

7:09 PM Allan, K7GT, asked about Field Day plans. The possible use of the Agate Lake location will be investigated, as it seemed most favorable of the proposed locations.

Official allocation of funds for Field Day expenses will be taken up at the next meeting on June 3. Mention was made of possibly operating in class 1A, if participants are few.

Below are some ARRL Field Day resources that are available online:

7:15 PM Club President Pat, KD7MPA, gave the first of tonight’s two programs: King Mountain Expedition. Pat presented photos and info about his visit to the 5254 foot elevation King Mountain, where the Peak Radio Association has a repeater on 146.940MHz, and some TV stations, and FAA, have transmitters. It is near a three-county junction, so is a good area for contesting. There was a tour of inside the repeater building. Some references: Steve Porter, WA6YSM, Sis-Q Communications, Patio Radio Network Peak Radio Association, W7PRA, Chris Novara, AB7BS Rich Zanni, KJ6RA

7:29 PM Discussion and comments, especially about difficult access during winter, followed. One story included the need to use a roof hatch for access when snow completely covered up the building.

7:40 PM Tom, N5EG, gave the second program, on SDR Measurements with Gnuradio. This is a preview of a program for the Gnuradio meetup planned for July 10th. A calibrated 5dB excess noise source kit from Miami Valley Ohio VHF/UHF Group was used for noise figure measurement. Dynamic range measurement was made by using a wideband display and adjusting input level attenuator to find the clipping level. Third-order intercept point was also measured with two tones input sourced from a 10MHz rubidium oscillator and an HP8560B generator through a 50ohm resistive combiner. Ideally a Wilkinson combiner would be used to get improved isolation between the two generators. Some effect of FFT windowing on the measurements was mentioned.

8:43 PM Discussion and comments followed. Tom mentioned that Dan Babcock, N4XWE, has some scripts for running Gnuradio 3.8 on Raspberry Pi, and can be found at github.com/n4xwe/Raspberry-Pi-Scripts

Other types of testing for SDR that are better than IP3 were discussed. Many other discussions on SDR, supply-chain issues, virtualization, Gnuradio, Field Day, filter and duplexer measurements, low-noise amplifiers, and other topics followed.

10:00 PM Meeting adjourned.

John, KF7UMK, Secretary

Tags: meeting