Home
The 50 MHz and Up Group is an educational and public service amateur radio organization centered in the San Francisco Bay area. The group is interested in developing and utilizing communications on frequencies from 50MHz up through light-waves. The group is open to any related topics that might be of interest to members, such as: technology, design, construction, operation, public service, contesting and antennas. Learn more . . .
Contact
For questions about this group or about programs and activities, please contact the 2018 President, Steve Shyvers (N6KLD): steve.shyvers (at) gmail [dot] com
2018 dues and member information must be updated
If you do not have any changes at all in your contact information, then simply send an email with a sentance to Jeffrey Pawlan satating that nothing has changed. Please use jpawlan@yahoo.com
To send a memberform with your updated information or to join, please go to the Membership tab of this website.
Dues are $10 for a year, $15 for two years. This can be brought to a meeting or sent to the new Treasurer:
Oliver Barrett
1111 Pecos Way
Sunnyvale CA 94089
Make your check payable to 50MHz and Up Group of N. Calif Inc
May 2018 Meeting Announcement
Our meeting location has changed
We no longer have access to the TI meeting facilities for our 50MHz and Up Group.
Our next meeting of the 50MHz and Up Group of N. Calif will be on Wednesday, June 13 beginning at 7:00pm. This is a different day of the week because of room scheduling. Note that this meeting will be in a community room of the Sports Basement located at 1177 Kern Ave, Sunnyvale. This is off of Lawrence and approximately across from St Johns. The meeting which will begin at 7pm and we must exit the building at 9pm.
Minutes of the May 2018 meeting
Steve Shyvers (N6KLD) called the meeting to order at 7pm.
The meeting started with announcements.
Announcements:
MUD 2018 will be in Dayton, Ohio, October 11-14. For more information see http://www.microwaveupdate.org/
The East Bay Amateur Radio Club is looking for speakers. If interested, contact Martin Rothfield, W6MRR. The clubs web site is at www.ebarc.org
The GNU Radio Conference will be September 17-21 in Henderson, Nevada. For more information see https://www.gnuradio.org/grcon-2018/
Central States VHF Conference will be in Wichita, KS July 26-29, 2018. A call for papers and presentations has been issued, with a deadline of May, 15th. For more information visit https://www.2018.CSVHFS.org
This was followed by a discussion of the July Picnic and Tune-up day
The location will be at the Ed Levin park, Sandy Wool Picnic area behind Milpitas. The date will be either July 21 or 28, determined by a pole on the email reflector. Art Lange moved that the club pay for the lunch, (probably Armadillo Willies barbeque). The motion was seconded, and passed by a show of hands.
Picnic Action Items, and Decisions
a) Steve will send email to group asking whether July 21st or 28th is better preferable to members.
b) We will not reserve a spot. We will depend on arriving early and staking a claim on several picnic tables near field.
c) Mike has test range equipment. Volunteers will be needed to help him test it prior to the picnic.
d) Club will cover cost of food and drinks. Recommended food is Armadillo Willy's. Need volunteer(s) to order and fetch food for 20 people.
There was discussion about adding 5 GHz to the tune-up equipment. No decision on this.
Oliver Barrett presented his finding regarding the AD6FP beacon performance.
- Field testing suggests degraded RX system, perhaps 15 dB down (beacon output estimated at +28 dBm ERP).
- Unstable freq. reference limits beacon and translator usefulness for users.
- Tower configuration makes separate radio or antenna system maintenance access difficult.
GOALS FOR DISCUSSION:
- Clean/recondition waveguide feed and TX/RX antennas.
- Hardware mods to support voltage conversion from proposed 12V battery backup system. (The decision was to provide a +12V to -48V inverter in the building.)
- Upgrade to use frequency-stable L.O. reference (but preserve good phase noise performance).
- Quantify TX desense at RX input, evaluate risk of improving TX/RX isolation design.
- Facilitate easier removal of radio module by itself for maintenance.
- Beacon feedback on RX sig strength.
SUGGESTED TIMELINE FOR COMPLETION THIS YEAR:
- Remove equipment from tower. (WA6QDP, N6JET, June 2nd or 3rd)
- Recondition antennas/feedline/flange connections. (WA6QDP)
- Determine radio upgrade configuration.
- AD6FP agreed to add phase locking of the LOs to a high stability reference, Add AGC telemetry on beacon CW ID, Reprogram control system so the beacon comes up in the on state after a power failure.
- Complete radio upgrades. (AD6FP +, ~ 1 week)
- Integrated system test/burn-in. (1-2 months)
- Reinstall system on tower. (August 5-6)
Tom Babut (SP5XMU) gave a presentation on VHF and Microwave in Poland and Europe.
The presentation was followed by a round table discussion of plans for the SBMS 2 GHz and Up contest.
The meeting adjourned at 8:55 PM
The 2018 Officers and Board Members
- President: Steve Shyvers (N6KLD)
- Vice President: Chris Veargason (N6JET)
- Secretary: Brian Kline (WA6QDP)
- Treasurer: Oliver Barrett (KB6BA)
- Board of directors:
- Art Lange (W6RXQ)
- Larry Zuckerman (K3LZ)
- Lars Karlsson (AA6IW)
Here is the presentation by Jeffrey Pawlan, WA6KBL on the history of circular waveguide, the use of low loss circular waveguide, transitions to rectangular waveguide, and expremely high performance dual mode feedhorns for 10GHz and 24GHz with builtin adapters to standard rectangular waveguide.
Please click here to view or download.Circular waveguide and horn antenna talk. This is a Powerpoint.
Beacons
Microwave Beacons in operation The following beacons are known to be operating as of 04-16-2016:
| Name | Grid | Coords | Freq | Call | Power | Ant | Comments |
|---|---|---|---|---|---|---|---|
| Mt Vaca | CM88wj | 38.415, -122.116 | 10368.325 | W6ASL | +30dBm | 10dBi omni | CW ID |
| Mt Allison | CM97bl | 37.500, -121.872 | 10369.192 10369.225 10368.625 24192.010 47061.017 |
AD6FP/R W6QI/B WA6QDP |
+17dBm +30dBm total out +17dBm +12dBm |
10dBi omni 12dBi omni open WG |
CW ID, drifts ~10 kHz Linear translator: Output is 11-55 kHz above beacon Input 600 kHz below desired output CW ID FM ID, aimed to Los Gatos |
| Mt Leeson | CM97ae | 37.167, -121.924 | 10367.990 24191.975 47087.99 79919.92 |
KF6KVG | +20dBm +20dBm +5dBm -5dBm |
2.5" horn 1.5" horn 1.25" horn 0.6" horn |
FM ID, locked, aimed NW FM ID, locked, aimed NW FM ID, unlocked, aimed NW no ID, locked, aimed NW |
| Bear Mtn. | DM06ir | 37.747, -119.281 | 24191.990 | W6BY/B | +27dBm | 20 slot omni | locked, IDs as DM07IC, will fix |
| Mt Frazier | DM04ms | 34.775, -118.969 | 10368.310 | N6CA/B | +31dBm | 14dBi omni | CW ID, locked |
| Heaps Peak | DM14kf | 34.235, -117.141 | 10368.370 | ? | +?? dBm | ??dBi omni | CW ID |
| Palos Verdes | DM03ts | 33.747, -118.336 | 10368.300 | N6CA/B | +32dBm | 14dBi omni | CW ID, locked |
| Santiago | DM13fr | 33.712, -117.534 | 10368.330 | KE6JUV | +27dBm | 10dBi omni | CW ID, locked |
| San Miguel | DM12mq | 32.697, -116.935 | 5760.000 10368.360 24192.050 |
K6QPV/B N6IZW/B K6QPV/B |
+34dBm +27dBm +34dBm EIRP |
10dBi omni 12dBi omni horn |
- CW ID, locked CW ID, locked, aimed to LA |