oops my bad!
However a couple of years ago I tried this MFJ product... https://www.youtube.com/watch?v=f5MB3f6jQ9w
It was OK...but dang it it sure picked up a lot of electrical noise!!! it doesn't help that our very close neighbors probably all have noise generating devices...
you can always give it a try and if unhappy, start playing with wire again...even a short piece of thin gauge thrown into a tree and then attached to your receiver might do the trick...
GOOD LUCK...apt/condo living and radio is not for the faint of heart!!!!
I'll second the advice from RFBOSS. A loop antenna may be the right answer for your needs. Were I in your shoes, I'd look in to something portable that can be broken down and moved. Households are terrible places RF-wise. You'll want to get this thing outside, away from all the switching power supplies, plasma TVs, light dimmers and the like.
Another vote for a magnetic loop antenna, given your situation this is the way to go as it is more immune to the RFI/EMI likely to be found indoors plus it is of compact size. They can be a bit pricey but they are also easy to homebrew. Do an internet search "magnetic loop antenna"... there is tons of info available, theory and practice and construction.
if it is just for receive, there are many options. here are my favorites based on owning them:
AOR LA400-small, portable, and works from 500khz up to 30mhz.
Quantum loop: small portable: 500khz to 6mhz.
Sony fold up active antenna: very portable and small. performance not as good as the two listed above.
for AM BCB only: crain twin coil antenna.
Hi what are you intrested to monitor raeson i ask main intrest for me is monitoring aircraft worldwide i do have active antennas and wire antennas did have the aor la400 loop couldnt even pick up my local ndb at my local airport which is 5 km away also had the mfj 1024 personally they didnt work me but if you are limited for space the wellbrook active loops will work okay.
Again, without knowing what you are trying to listen to - all the advice given is just pissing in the wind!
If you are looking to receive HF - then you need a decent sized antenna or a directional antenna. http://www.monitoringtimes.com/antennabook.pdf
If you want to listen to the broadcast band, then a meger loop antenna will probably get you something.
You didn't say what kind of receiver you use. Some of those cheap Chinese pieces of crap, the price of the antenna will double the cost of the system.. Tecusun etc..
This is the antenna I have suggested in the past for reception of 7 Mhz and up.. Home
A really good high level active whip can do very well if placed outside and away from noise generating equipment. These are not something you would find from MFJ or similar mfrs and they can be quite expensive new. You would want to place this type of antenna outside on a balcony at the least and preferably on the roof attached to a vent pipe, etc.
I've got an AMRAD active whip which was a semi kit and ran me about $75 in parts and took several hours to build. It works really well and not too far behind a PAR SWL end fed on the SW bands. On MF and VLF the AMRAD greatly outperforms the PAR end fed. The AMRAD has some of the best specs out there for any active whip.
You can usually tell the difference between a high performance high level active whip over cheap overload prone versions by the power it consumes to bias the higher level transistors used in the better designs. If the active whip runs on a 9v battery or uses 12v at 50ma or less its not in the high performance league. If it needs 12v at 100ma or more or 24v at 50ma or more then your looking in the right direction.