ka3jjz
Wiki Admin Emeritus
We've covered what you can do in a tiny yard - but what about in a high rise or similar where you can't get anything outside?
You're going to be at the mercy of the construction of your home, and all the noise sources found there. There's no way to completely get around that. But if you have an attic, (I did for awhile), you may have an out. Putting an active loop in the attic is likely the best you would be able to do, if there's enough room for it. I wish I had known about the W6LVPs and others when I lived where I had a large attic. Sure would have made HF easier! You may even find that common mode chokes will cut the noise down further, but this is very much a case by case thing. They don't always work for everyone.
Nut what if you have no attic? Well there are a few solutions
First, let's avoid these broad band active antennas - they're likely going to be more trouble than they're worth, especially if you can't find a quiet spot for them (hunting with an old AM band portable is a cheap way to find them, if there is one). So we want something that's tuned; this is especially true if you want to try to reject all the RF crud from FM, TV and other sources (and if you're living in or near a city, who wouldn't?)
I had something like this quite a while ago
It worked OK for what it was, but it amplified noise a lot more unless you really rode the gain control (and you shouldn't run something like this full out anyway...).
Some of you who've been around awhile will recognize the names Kolb and Sanserino. They put out a fine preselector that could be used as an active antenna, and was marketed through Radio West. I had one - gave it to the Handicapped Aid Program when they were still around. Really wish I could still find one, but they are ultra-rare to find anymore.
Loops are going to be helpful in rejecting at least some of the noise. Sadly indoor amplified HF loops have largely been abandoned. Palomar had one (and so did I for awhile, until the antenna plug in connection failed), as did Kiwa and even Quantum Loops - all gone. Plans for MW loops can be found a lot easier than this.
Passive loops - like the YouLoop and the Doxytronics (currently out of stock) are popular but better for these SDRs that have hot front ends - like the RTL SDR v3 and FunCube, as well as some portables (we have plans for building your own YouLoop in our Loops wiki if you're interested). Signal pickup with these tends to be rather low (I understand there's some folks working on an amp for the YouLoop). What if you need a bit more?
This comes from Australia, and it's likely to be more affordable for our Pacific and Asian DXers; take a look at this link, and select the 'Antennas' pulldown..
www.amradioantennas.com
with some reviews;
Mike
You're going to be at the mercy of the construction of your home, and all the noise sources found there. There's no way to completely get around that. But if you have an attic, (I did for awhile), you may have an out. Putting an active loop in the attic is likely the best you would be able to do, if there's enough room for it. I wish I had known about the W6LVPs and others when I lived where I had a large attic. Sure would have made HF easier! You may even find that common mode chokes will cut the noise down further, but this is very much a case by case thing. They don't always work for everyone.
Nut what if you have no attic? Well there are a few solutions
First, let's avoid these broad band active antennas - they're likely going to be more trouble than they're worth, especially if you can't find a quiet spot for them (hunting with an old AM band portable is a cheap way to find them, if there is one). So we want something that's tuned; this is especially true if you want to try to reject all the RF crud from FM, TV and other sources (and if you're living in or near a city, who wouldn't?)
I had something like this quite a while ago
MFJ-1020C, ANTENNA, SWL INDOOR ACTIVE ANTENNA
MFJ Tunable Active Antenna MFJ invented the tunable active antenna! New technology uses a cascode FET/bipolar transistor and a gigahertz bandwidth buffer.Numerous copies have been made without success -- including most recent ones. Why? Because MFJ has made continuous improvements where others...
mfjenterprises.com
It worked OK for what it was, but it amplified noise a lot more unless you really rode the gain control (and you shouldn't run something like this full out anyway...).
Some of you who've been around awhile will recognize the names Kolb and Sanserino. They put out a fine preselector that could be used as an active antenna, and was marketed through Radio West. I had one - gave it to the Handicapped Aid Program when they were still around. Really wish I could still find one, but they are ultra-rare to find anymore.
Loops are going to be helpful in rejecting at least some of the noise. Sadly indoor amplified HF loops have largely been abandoned. Palomar had one (and so did I for awhile, until the antenna plug in connection failed), as did Kiwa and even Quantum Loops - all gone. Plans for MW loops can be found a lot easier than this.
Passive loops - like the YouLoop and the Doxytronics (currently out of stock) are popular but better for these SDRs that have hot front ends - like the RTL SDR v3 and FunCube, as well as some portables (we have plans for building your own YouLoop in our Loops wiki if you're interested). Signal pickup with these tends to be rather low (I understand there's some folks working on an amp for the YouLoop). What if you need a bit more?
This comes from Australia, and it's likely to be more affordable for our Pacific and Asian DXers; take a look at this link, and select the 'Antennas' pulldown..
PK's Loop Antennas
with some reviews;
A preliminary review of the PK Loop C-LOOP-HDSW6-18
Over the past year, a number of SWLing Post readers have asked me to review the PK Loop portable magnetic loop antenna produced by Paul Karlstrand in Australia. I finally caved in and purchased one…
swling.com
A follow-up review of the PK Loop C-LOOP-HDSW6-18 antenna
In 2016, I purchased portable shortwave magnetic loop antenna designed and built by Paul Karlstrand in Australia. I posted a “preliminary” review of this antenna in 2016 and since then …
swling.com
Mike
