Outdoor FM Antennas Used Indoors (Urban)

I live in midtown Manhattan in a high rise building and have a significant multipath interference problem. I have just bought a Marantz 10B tuner and need help weighing my options with regard to outdoor antennas used indoors. I have read the literature of Magnum Dynalab and Fanfare regarding their ST-2 and FM-2G antennas respectively. The two antennas seem similar if not completely identical. They both are omnidirectional and both claim to significantly reduce multipath distortion. This seems to be an impossibility to me, that an omnidirectional antenna can significantly reduce multipath interference. So, what I am asking is if someone living in an area similar to mine (in a steel reinforced concreate building with lots of nearby tall buildings) can actually vouch for either or both of these antennas as having significantly reduced multipath distortion particularly when either or both of these antennas are used indoors. I have read all the recent Audiogon threads on FM reception. Some suggest the use of the Magnum Dynalab Signal Sleuth. I'd like to avoid major additional expense and extra "boxes" if possible. I have tried the Terk powered antennas, the BIC beam box etc. with other tuners I have owned and while better than the FM "T" antennas, I am looking for something better. Don't want to go the "cable" route either unless I get desperate. I'd just like to get the performance that the 10B is capable of. Let me know if either or both the MD ST-2 or Fanfare FM-2G can do the job alone. Any comments about what improvements were offered on top of these antennas by the Signal Sleuth would be appreciated. Thanks in advance for all your good advice!
The Signal Sleuth has been very well commented upon by some of the most objective of sources (how else to evaluate an antenna/aid?). The scope in the 10B should assist you greatly in orienting your antenna for minimal multipath. With a sufficiently large attic space, I would install the largest motor directional yagi that I could and let the 10B work its magic. If you're still dissatisfied, try to find a clean MR78. As an aside. Some cable tv companies also feed FM through their cables. If it's there, you only need a signal spliter.
Might need to actually coaxially PAD the RF signal input in an environment like that. Try 3dB, 6dB 10dB etc... See if you can attenuate the weaker out-of-phase signals enough to improve things, without weakening the main signal too much in the process. That might help alot in your high-field-strength metro area, at least for the local stations. The Sleuth will attenuate as well as add gain (front knob adjustable). Since multipath is same-frequency interference, the benefits of Sleuth's narrow band preselection may not help in that regard, but I believe the attenuation would. I've had a Sleuth & FT101 for many years; both are wonderful for 60-miles-out FM.
I own the FM-2G and a Fanfare FT-1A. I've found that the FM-2G is very sensitive to location. When it was indoors I wasn't "wowed" with the whole set-up. When I moved it out on the balcony, NW corner and covered, and hung it from the cover/roof it really didn't sound any better except that I could now walk around the listening room without distorting it ever so often. However, once I got it mounted on the eaves of the roof so that it could receive from both sides and above, not to mention the fact that it was now six feet higher, it sounded considerably better. I'm still experimenting with it. Strangely enough though, the Fanfare tuner actually tunes quicker under scan mode or when I'm just going from one preset to the next with the antenna in the good/better position. I own a very nice hifi system and have been into audio for awhile, but I've never invested in a high-end tuner so I don't have much experience at this sector. I know antenna specialties has an indoor mount antenna that they claim is very good and much better than the "whips" if you're willing to pay the extra money, its only $300 and the unfinished version is only $150. To address one more point, my location and building are nothing like yours. I don't know thier website but someone lists it in one of thier reviews on audioreview.com under the tuner section under one of the reviews for the aps-13 which is antenna specialties yagi style. It may be antennaperformance.com or antennaspecialties.com. Good Luck.
Its antennaperformance.com; Its called the "In-tenna" and the finished version is actually $400.
dunno about antenna perf-specialties' "in-tenna", but i got one of their aps-13's on the roof, & it gives great reception in an otherwise completely unlistenable environment. doug
I have an outdoor antenna in my attic. I tapped it into the cable TV wire going to that room. So all I had to do was plug the tuner 75ohm connection into the wall. Works fantastic.