and clean signals
the publication of
The 50 MHz and UP Group of Northern California, Inc.
Volume 3 Number 9 September, 1998
(Edited by Rex Allers, KK6MK)
Visit our web site at: http://www.nitehawk.com/rasmit/50UP.html
Next Meeting: TUESDAY, September 1, 7:30PM - at Lockheed Bldg. 202.
PROGRAM: The Use of Precision Quartz Oscillators and Atomic Standards in Ham Radio. Presentation by Rick Karlquist, N6RK.
Rick works at Hewlett-Packard Laboratories. He has been an RF circuit designer on the HP E1938A and 10811F quartz oscillators, 5071A cesium frequency standard, and 10816A rubidium frequency standard. He was also project manager on the HP 5334B frequency counter. He has been licensed since 1965.
DIRECTIONS: The meeting place will be the Lockheed Auditorium in bldg. 202 on Hanover St. in Palo Alto, California. Access Hanover from Page Mill Road (between 280 and El Camino). Follow Hanover as it curves right and up the hill. Watch for the Lockheed sign indicating Bldg. 202 on the left side, about 2/3 of the way up the hill.
Officers for 1998
|Vice President||Jim Moss||N9JIMemail@example.com|
|Board Member||Jeffrey Pawlan||WA6KBLfirstname.lastname@example.org|
|Board Member||Bob Johnson||KF6KVG||415-854-5117|
|Board Member||Sam Wood||K6MSRemail@example.com|
Contests and Events
Foothill Swap Meet - The second Saturday of the month.
Livermore Swap Meet - First Sunday of each month at Las Positas College in Livermore, CA, 7:00 AM to noon, all year. Talk in 147.045 from west, 145.35 from the east. Contact Noel Anklam, KC6QZK, (510) 447- 3857 eves.
ARRL 50 MHz-Up Contests
September 12-14 ARRL September VHF QSO Party
September 19-20 ARRL 10-GHz Cumulative Contest (2 of 2)
A special swap meet
Subject: [WSWSS] Swap Meet CM98
From: Larry Hogue <firstname.lastname@example.org>
Hello Hello to all.... Well the Weak Signal operators in Northern California are gathering again...We are going to try a swap meet, grip and grin, and just plain old bring you lawn chair and enjoy the day...Ill have the pop, water and a little shade...
Where... Here!!!! 7372 Paddon Rd, Vacaville, CA 95688
Date.....5 Sept 98
Time.....8:00-1200 Local Pacific time..
We have Mike Staal, K6MYC and his Lovely Bride, Myrna, WA6GXF from Mē coming, Richard, KA6NBC of AntennaWorks joining, and working on Norm, KB6KQ of the famed Mini-Loops.
The day is planned as a easy day, just plain old gossip and Amateur Bull...
The place here is located just North of Vacaville, one mile west of the exit of I-505 and Midway road.. Soooo coming south on I-80 or I-505 you would turn right and proceed to Paddon Rd. Turn right and we are the second and third drive ways on the right... Look for the antennas. Coming north on I-80 or I-505 just turn left... hi hi
We have 5 acres, so I think we will be ok... Its a "Ham" swap meet... So bring your best and let me know if you need further directions or information...
Sue and I are excited and hope you can join us and share part of your Labor Day weekend...Don't forget the Livermore Swap meet is the next day...
We are only three miles north of the Nut Tree Airport and the Nut Tree Factory Outlets... Plenty of things to do...
Do we need to pick you up at the airport?? Does the family need a brochure?
What else??? Let me know and Ill fill...Many thanks and see ya soon...
- 73 W6OMF LARRY & K6SUE SUE.
New members welcomed
We are always looking for more people to join and share with our group.
At the end of 1997 a vote was unanimous to reduce the dues back to $15.00 per year. It was also decided that a special rate of $25 for two years be implemented.
Please encourage anyone who might have an interest to join our group.
VHF+ WeakSignal NETS
|Sunday||8PM||144.240||Southern California WSWSS|
|Sunday||8PM||144.250||Central California WSWSS|
|Sunday||8:30PM||432.100||Central California WSWSS|
|Tuesday||8PM||144.250||Northern California SWOT|
|Wednesday||8PM||144.240||Southern California WSWSS SWAP|
|Thursday||8PM||144.250||Northern California SWOT SWAP|
|Thursday||8PM||432.120||SCAL General, Oceanside, DM13|
50 MHz & Up Group Minutes
The August meeting was cancelled, so there are no minutes this time.
10 GHz and Up Contest
The weekend of August 15-16 was the first weekend of the ARRL 10-GHz and Up contest. I got my rig working again just in time. I enjoyed myself making several local contacts. Sunday I went up to Loma Prieta with Ron Smith, K6GZA. Ron made four contacts, that day, down to Southern Cal. I don't have the details of the four, but at least one was over 400 miles. Two were CW but two were SSB!
We will see if we can get some more reports from other participants at the September meeting.
Hope to see more people out for the second weekend of the contest, September 19-20.
50 MHz and Up Group Shirts
The shirts have our club logo on the back in color and our club name on the front. Members who were at the June or July meetings have seen them. For those that have not seen it, the logo is similar to the image in the header of this newsletter. If you have Internet access you can see the logo in color on the Group WebPages listed at the end of the newsletter.
Polo Shirts $18.00
Sweat shirts $25.00
The polo shirts are short-sleeved shirts with collars and a few buttons at the neck.
Please decide quantities for any shirts you would like to order and contact me. You can call me at home (my telephone number is listed in the member list) or email me email@example.com or bring your order request to the next meeting.
THE VHF EVENT OF THE YEAR!
Western States Weak Signal Society 1998 VHF Conference
Saturday, October 3, 1998
Sunnyvale Hilton, Sunnyvale, CA
Sponsored by: The 50 MHz and Up Group of Northern California, Inc.
Schedule of events:
Saturday, October 3, 1998
9:00AM 12:00PM Papers and Presentations on two tracks (Technical and General)
12:00PM 1:00PM Luncheon (included in conference fee)
1:00PM 5:00PM Papers and Presentations on two tracks
5:00PM 6:30PM Cocktails and conversation
6:30PM - - - Banquet
Sunday, October 4, 1998
Dawn Livermore Hamfest, in Livermore (30 min drive)
Conference Fee including luncheon ($35 per person)
WSWSS VHF and Awards Banquet ($35 per person)
Special discount rates are available to WSWSS participants at the Sunnyvale Hilton.
1-408-738-4888 or 1-800-HILTONS.
Call now to reserve rooms Oct 2-4 for $69 single/double occupancy.
Reservations at discount rate only available through 9/4/98.
There is easy access from US101 at Lawrence Expressway to the Sunnyvale Hilton.
San Jose International Airport is only 5 minutes away.
Great Family opportunities:
Paramounts Great America is only 5 minutes away!
Silicon Valley and San Francisco sites are all close by.
Wine Tasting available both in the Santa Clara and Napa Valleys.
Marine World Africa USA in Vallejo.
Other ham activities:
Livermore Hamfest is on Sunday AM.
HRO Sunnyvale is a walk away.
Frys Electronics is 2 minutes away.
Numerous Silicon Valley surplus stores open Weekdays and Saturday.
For more information: See the WSWSS '98 website at: http://www.qsl.net/wb9ajz/wswss98
A Satellite Converter with an Interesting LO
Last year I didn't make it out for the 10-GHz contest because my microwave local oscillator (LO) stopped working. I designed my radio for a high-side oscillator I was able to find. I used some DMC RX and TX parts that were designed to create a 300 MHz IF. I then mixed again high-side to flip things back and convert to my radio frequency. To keep the same design I needed an LO at about 10.680 GHz. As luck would have it, I stumbled on a solution at a flea market a few months ago.
Below are pictures of a satellite down converter I found recently. I know there were a few of these around, so maybe other members have them. The ones I have seen all had a U-shaped waveguide (WR 75) on the input flange. It is "AORSAT 1000A PLL" for 11.7 - 12.2 GHz. It also says "External Reference" on the cover. This sounded interesting. I wondered what the PLL and External Reference meant.
I opened up the covers and examined the circuits inside. One side was the RF preamp, mixer, and block output amps. Per the cover, the low noise RF preamp is pretty good -- marked at 1.2 dB NF -- but that's not really what I wanted from this thing. The other side had a DRO for the LO. The oscillator output seemed to be sampled and ran into a little brass shielded box. This appeared to be some kind of PLL sampler for locking the oscillator to a reference.
I experimented and found that this was a standard satellite converter, but with an added twist. Most of these things convert the microwave signal down to about 1 GHz which is feed out through a 75 ohm TV-style connector. The same coax that feeds the output RF away is also used to supply DC voltage for the operation of the converter. I applied +15 Volts to the connector and found that by holding a probe near the open unit, I could detect an LO signal at around 10.8 GHz.
I thought that this thing might also be designed to pick up a reference frequency from the same output cable. I inserted a DC block on the output connector and fed an oscillator signal in (along with the blocked +15 Volts). Sure enough when I injected 10 MHz, the Local Oscillator in the unit locked to 10.750 GHz. Great trick, but unfortunately too high in frequency for me.
Maybe somehow I could modify the PLL counters to get a frequency I could use. I examined the circuit and didn't see anything that looked like a PLL counter chip. Could this be a simple injection mixer?
I soldered a wire on what appeared to be the control voltage signal for the DRO. I checked this signal. With no external reference this was a sawtooth and with the reference connected so the oscillator locked, it was about 10 V dc. Good so far now I had a way to monitor lock. I loosened the adjustment screw on the DRO and started to turn. Lost lock then lock frequency now 10.740 GHz. Tune more. Loss lock 10.730. Dang! This thing locks every 10 MHz.
I was able to adjust it down to 10.690 and still maintain dependable oscillation with lock. This was good enough for me to use with my existing 10 GHz rig. Now I just needed to find a way to tap into the oscillator output.
After the sampler out of the oscillator for the PLL, there was a printed filter in the main signal path. This must be designed for 10.750 but maybe it will pass signal at 10.690. I made some rough signal measurements on the mixer side at 10.750 and 10.690. The signal did not appear to be too far down, so I didn't attempt to modify the filter.
I found that there was enough room to add an SMA connector right at the end of the LO filter. I unsoldered the rod feeding the LO signal from the filter to the other board. This was hard to remove and I am not sure if it was necessary. I might not do this if I tried again. I drilled the case and added an SMA connector which I connected to the filter with a short piece of silver plated wire. All that was needed now was to cut a slot in the end of the filter cover to allow the wire to pass. The modifications are shown below.
By using a good 10 MHz ovenized reference oscillator to feed the converted unit I was able to use it as my microwave LO and stay right on frequency all day. That's a first for me and was a nice change -- eliminating the frequency uncertainty I usually had in the past.
In my application I made no use of the preamp or mixer in this unit. The only bad news was that the strength of the signal out through my added SMA connector was only about 0 to +1 dBm. I needed about +10 dBm so had to add an amplifier after this source before I could use the signal.
Well, I hope you found this interesting and I hope someone in the group has one or two of these things and someone can put them to use besides me. If anyone wants more details on what I found or how I did this, please contact me. I'd be happy to give more details.
- Rex Allers, KK6MK
On the Internet
Do you have a Web Page relevant to our
members? Let us know and we will put it here. (You must be
50 MHz and Up Group page: http://www.nitehawk.com/rasmit/50UP.html The official group web page. Hosted by Rein Smit, W6/PA0ZN as part of his Weaksignal News Kiosk. The 50Up page includes an archive of newsletters.
ARRL Pacific Division Web page: http://www.pdarrl.org/
Rex's Place - KK6MK: http://www.dnai.com/~rexa/ Microwave stuff, 50 MHz Up Group pictures and information.
Laser Communications Home Page! http://www.qsl.net/wb9ajz/laser/laser.htm Lots of bright stuff.