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Technical Topics => Equipment => Topic started by: William Hassig on July 14, 2019, 0157 UTC

Title: Active antenna for condo or apt
Post by: William Hassig on July 14, 2019, 0157 UTC
I've been thinking about moving into a condo in the future. I'm 73 and tired of taking care of a 92 year old house that has problems. This means I would be giving up my 7mhz backyard dipole and CB antenna. I would like to know if anybody is using an active antenna in a condo or apartment and how good the reception is. I fear there would be too much QRM in a multiple unit building. Thanks for any answers.
Title: Re: Active antenna for condo or apt
Post by: ThaDood on July 14, 2019, 0535 UTC
Well, I've been APT bound in the past, and even lived on the GND Floor of a complex, and have tried just about everything, including active antennas. And, every APT will be different with its perks and jerks. How high up will you be? Will you have access to large window panes? What kind of night time lighting is used, sulfur vapor, halogen, LED? Don't get me wrong, HF DX'ing is still possible, but between indoor attenuation and internal noise, it will be a great challenge. In the GND Floor of an APT Complex I did DX several pirates, like Radio USA, but I remember it being a real stretch to get that ID in 1990. Conditions like that prompted me to getting my codeless HAM ticket when that came 2/14/1991 in the USA, since I was able to get out better on VHF and UHF bands. Still I worked CB, as well as heard a lot of 10M stuff. For 13MHz - 30MHz, an 11M CB homebrew dipole in an Inverted-V can work almost as well as an outside mobile set-up. (Almost.) Fine-tweak with an antenna tuner, and maybe even an RX preamp, (With adjustable gain.), and there ya go, a homebrew active antenna-like system. You maybe surprised just what you can RX below 13MHz as well. I don't know where ya are, but you still have some nice propagational 24/7 beacons out there, WWV 2.5MHz, 5MHz, 10MHz, 15MHz, 20MHz, and now 25MHz. Then, Canada's CHU at 3330kHz, (And the 40M and 20M FREQ's escape me, at the moment. Brain fart.). Oh, then 24/7's CFRX 6070kHz 1kW from Toronto, ON, Canada. Then, look for listing for amateur radio 10M Beacons. I hate to say that you will miss what you have. If you have windows that can open up, then another trick that I've done is a wire hanging from a fishing pole out the window. Reel it out when ya want to DX, reel it in when you're done, and hide it, even in an HOA-like environment restrictions. Oh... I even ran super thin TV degausser wire to a near-by tree. The only way someone had seen it was to know what they were looking for, and I DX'ed pirates, Euro and Russian stations with that. I don't envy ya, but I hope that this these are some ideas of what you can try in a condo, and they maybe cheaper than shelling out for an active antenna that may just bring you in more noise than signal. In a pinch as well, you also have on-line SDR stations to monitor, but that's not the same as RX'ing with your own gear, is it? 
Title: Re: Active antenna for condo or apt
Post by: Josh on July 16, 2019, 0349 UTC
My last apt was ground floor, and right outside the door was the fire alarm system for the complex that had s9 noise spread around hf. What a mess. Sneaking a wire thru the window screen across an area that didn't see much foot traffic was key to getting cleaner signals, at least until they mowed the wire apart.
Title: Re: Active antenna for condo or apt
Post by: ChrisSmolinski on July 16, 2019, 1150 UTC
Independent of the lack of space for putting up an antenna, or HOA Antenna Nazis that won't allow anything outside, you'll also likely suffer from the increased RFI/QRM you mentioned. If you have access to your attic (and will be allowed to use your attic) you could consider a magnetic loop for transmit/receive. They're compact.
Title: Re: Active antenna for condo or apt
Post by: Josh on July 16, 2019, 2057 UTC
Dunno if hoas can keep one from erecting a flagpole, some flagpoles make for lovely hf antennas and no one's the wiser.
Title: Re: Active antenna for condo or apt
Post by: ChrisSmolinski on July 16, 2019, 2136 UTC
Dunno if hoas can keep one from erecting a flagpole, some flagpoles make for lovely hf antennas and no one's the wiser.

Looks like they do try to ban them from time to time: https://www.allpropertymanagement.com/resources/ask-a-pro/posts/q-can-hoas-prohibit-flags-flagpoles-properties/

My guess is if you put one up and the HOA complains, contact your local VFW and invite a few dozen vets, along with the local media, over for a photo op.

You can invite the HOA to the photo op as well, but I suspect they will decline.

More good info here: https://www.nolo.com/legal-encyclopedia/can-your-hoa-prohibit-you-from-flying-your-favorite-flag.html

Looks like pro flag legislation (probably in response to perceived anti flag activities) might prove beneficial to radio hobbyists facing overly restrictive HOAs (as if there's any other kind).
Title: Re: Active antenna for condo or apt
Post by: pjxii on July 22, 2019, 0243 UTC
I've been thinking about moving into a condo in the future. I'm 73 and tired of taking care of a 92 year old house that has problems. This means I would be giving up my 7mhz backyard dipole and CB antenna. I would like to know if anybody is using an active antenna in a condo or apartment and how good the reception is. I fear there would be too much QRM in a multiple unit building. Thanks for any answers.

If you're looking for a receive only option (I believe that's what you're asking), I am having good luck with loopstick antennas. I can either turn the antenna away from the noise source, though apparently my problem source is only in one direction. If noise comes in from all around it'd be more difficult. Or, since the ones I've used run off internal batteries, there's always a spot in every apt/condo I've been in that is a sweet spot for low noise, or lower at least which can be turned away from.

The Palomar LA-1, AOR LA-320 and Palstar LA-30 have all worked pretty well here (maybe that should be Pal$tar).
Title: Re: Active antenna for condo or apt
Post by: Looking-Glass on July 24, 2019, 1539 UTC
I once lived in a top floor apartment and put up a 27MHz CB antenna 1/2 wave vertical clamped to a wooden broom handle on the balcony and it worked wonders, I took it down and laid it across the balcony when not in use.

Had great coverage from around 12MHz through to 29MHz receive only.

Also used a very thin copper wire dipole mounted on the inside of the large bedroom window with suction cups, also had reasonably good performance from that.

The old 300 Ohm TV ribbon lead also used to make a good indoor antenna, using Blue Tac to secure it and run it around the ceiling skirts. Worked quite well as a tiled roof and not iron.

Another method I used was thin strand plastic coated copper wire (bought that by the yard off a reel in Radio Shack), I tied a bolt on the end of it and threw it across the entire roof length and run it back through the bedroom window, it worked exceptionally well and not visible to snoopy neighbours...   ;)

For VHF I used a VHF/UHF indoor TV antenna with two long rabbit ears (each ear telescoping to around four feet in length) and a arch shaped wire loop at the bottom mounted to the base.  This achieved exceptional results mounted on the window sill against the glass, maritime, aviation and amateur radio repeaters on 2m band all came in very well, also heaps of stations on the FM  radio broadcast band, some over 100kms away quite audible.  For $35.00 at the time it was exceptional value! ;)