I've been asked to put on Internet the Condo Communications newsletter. This has previously been circulated on packet and in a modified form on Hap Holly's R.A.I.N. (Radio Amateur Information Network). Enjoy!--WA5OES
==============================================================================Welcome to the second exciting, thrill-packed issue of Condo Communications, a newsletter devoted to those amateurs who, for various reasons, must configure their stations to operate from restrictive areas such as condos, apartments, townhouses, neighborhoods with outdoor antenna restrictions, ships/boats, mobile homes, or wherever they fry their burgers and call QTH.
Seems just about everyone has lived in an apartment at one time or another. John, WB5OAU reports:
I operated several years out of a studio apartment, with indoor antennas (Worked all states in one year!) ... it is possible! Keep up the good work...73/john WB5OAU @ WB2ARS.NM.USA.NA
Of course, you might just operate as much as possible away from the home QTH, as Glenn, AE0Q, shows us:
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And then some of us live in Faraday cages, as Dave, AJ5F, and XYL, N4TCH, report.
Our version of the "American Dream" was a condo on Miami Beach. We got a great deal on an 11th floor penthouse with a fabulous ocean view that 10 million northerners and Canadians would kill for. Problem: How do 2 licensed hams continue their hobby from said QTH? The attic is a concrete slab 6 inches thick and the condo association said "No antennas on the roof" (after the work the hams here did during Hurricane Andrew, I may get them to change their minds). Sooooooooo.....antenna is a truck mirror- mount base bolted to the railing on our back porch balcony with a 7 foot tall house plant behind it. The house plant is a perfect disguise. There's a 2m/70cm mobile antenna screwed into the base. I use this for packet, and ragchew on 440. To work HF, since there is only one feedline, and I don't wanna press my luck by running another, we unscrew the 2m/70cm antenna and put in a 20 meter mobile whip. I run a TS-520 with full output (SWR is 1.8:1) with no RFI/TVI (guess the TV cable system here is well built).
The one thing that worries me is grounding. (This is particularly a problem with high-power transmitters - KE4LAC)Currently I have a piece of copper bare wire running about to feed to a steel window frame, hoping there might be some ground through the rebar system of the building's structure. Haven't had a problem yet, but who knows? 73 de Dave AJ5F @ W7LUS.#HWDFL.FL.USA.NA
Good question, Dave. For an RF ground, you might try an artificial ground (see the bibliography for a reference). Those of us clustered into townhomes, condos, and the like have a tougher time trying to find a good electrical ground. You could try the frame on the electrical socket, but the ground for it may be pretty far away and actually radiate a signal if it's a multiple of a wavelength. How far away is the copper pipe in your bathroom? So, by making a good electrical ground, you may actually worsen your RFI problem. But for those of you fortunate enough to be near to Mama Earth, see the next section: Technical Correspondence.
Now, let's hear from the rest of you. Does anyone operate QRP from a seemingly impossible situation? (After all, I've heard guys who refuse to upgrade to get HF privileges...they live in apartments, so what's the use?). How about QRO. Anyone successfully running maximum legal power from a condo or townhouse? How about running lots of power operating off of batteries or generators, like from a boat or RV? And is it even possible to operate the fancy satellites (like 8J1JBS) from a condo? Or do you keep your satellite rig in the trunk of the car, with antennas strapped to the ski racks, and operate portable only?
Did someone mention grounding? N3LSY responds!
Regarding your question as to whether grounding helps with RFI in part 3, I can answer yes. I live in a townhouse and use some rather vintage Hallicrafters gear for my HF work. This is old tube type gear that puts out about a hundred watts or so. I was able to get rid of over 90 percent of my RFI problems, which included TVI, telephone interference, and getting RF burns in the shack by grounding the receiver, transmitter, T-R switch, and Tuner to an eight foot ground rod discreetly sunk into my flower bed, using #10 wire to tie everything together. Indivdual needs may vary, but use good connectors, heavy wire, and keep wires as short as possible for best effect. This will not only make you a better neighbor, but increase the safety and effectiveness of your shack. N3LSY @ WB3V.MD.USA
Makes sense. After all, when you look inside your equipment, stray RF is bypassed to the chassis through capacitors. You have to provide that final leg of the connection to ground. Now, how many of you perched in strange nests have found clever ways to make that electrical connection without radiating harmonics?
Anybody with more RFI hints? Is there a solution to fundamental overload (overpowering all channels)? How can you avoid coupling into the AC mains with your ceiling-mounted beam? Also, let's hear about the really wacky stuff: using your local 440 Mhz 9600 baud LAN to swap huge program or graphic files (is anyone even doing this?), running a packet gateway from a hideaway, bizarre antennas (especially involving gutters, lawn chairs, or metal siding). Did any of you operate clandestine radios for the military? Can you run 10 Ghz equipment from your 30th floor balcony? How about ATV?
I wish to thank my good friend here in Denver, Glenn, AE0Q, for providing the following references.
1. Orr, Bill W6SAI
Telephone Interference Revisited
CQ
June 1991
pg. 70 Collection of reader's solutions.
2. Rogers, Buck K4ABT
CQ Reviews: The AEA ISOLOOP HF Antenna
CQ
July 1990
pg. 18 On-air tests and contesting with antenna.
3. Ingram, Dave K4TWJ
CQ Reviews: The Forbes Group VENTENNA
CQ
May 1992
pg. 58 2m/440mHz disguised antennas, roof mount
or indoor use.
4. Johns, Robert W3JIP
How To Build An Indoor Transmitting Loop Antenna
CQ
Dec 1991
pg. 30 Part 1 - 10 thru 20 meters
Jan 1992
pg. 42 Part 2 - 40 and 80 meters
Constructed from copper tubing, can be broken
down for portable use.
5. McCoy, Lew W1ICP
The McCoy Dipole and How It Came To Be
CQ
June 1992
pg. 11 Theory and construction of all-band dipoles
that can be made ANY convenient size. Good for attic
installations!!
6. Pollock, John KA7MCX
But Will They Come?
CQ
Aug 1992
pg. 50 AEA Isopole 2m antenna in a disguised
installation, used for bird feeder support!
to which I will only add:
7. Brumbaugh, J. Frank KB4ZGC
Artificial RF Ground
73 Amateur Radio Today
April 1991
pg. 10. A nifty little construction article. I built
this device when I was running an end-fed wire strung
all over the townhouse. Didn't do much to reduce TVI
for me, but did provide a counterpoise to that string
of random-length wire.
8. Gibilisco, Stan W1GV
Apartment Antennas: A Challenge
73 Amateur Radio Today
May 1991
pg. 42. A must read for the apartment dweller. All kinds of
things you can do with wire and a tuner. A very good overview
of restricted space antennas.
9. Hines, Jack G. K4GIO
Visual Aids for Tuning Small Loop Antennas
The QRP Quarterly
October 1992
pg. 6. If you operate an IsoLoop type of antenna, this article
shows some tricks for speedier tuning, using the MFJ SWR Analyzer
or a noise bridge.
What have YOU been reading? Pass it along!