And by attenuation you mean getting some attenuation module and plugging it into my scanner, also would a 536hp work better than what I have now or should I just go all the way and get the sds200?
You can set attenuation (for the P2 scanners, 325P2 or 996P2) in either a specific site (trunked systems), or per channel (individual conventional frequencies).
Attenuation might help to block some of the weaker signals, from the more distant transmit towers in the simulcast system. In this case, you would set it at the site level. Occasionally, though rarely, it might help receiving the simulcast site. Doesn't cost you more than a few minutes of your time to try it. While for some locations, it may work, or maybe not. The 'does not help' responses seen in posts confirms this may be a long shot. If it works for you, great. If not, then try something different.
For the database scanners (x36HP and SDS series), you can also set attenuation globally, meaning
all sites & conventional channels are attenuated, so it takes a stringer signal for the scanner to hear any of the sites & channels. Attenuating everything also would likely preclude your receiving some of your more distant systems.
You could buy a 536HP, but purchase it from a vendor that does not heavily penalize you with restock fees if you need to return it because it did not do what you needed. ScannerMaster is one possibility, as is Amazon, and (I think) Bearcat Warehouse. That way, if the 536HP struggles as well on the simulcast, then you won't take a large restock fee or other penalty if you have to return it.
Keep an eye on the Uniden Prospective Owners forum. If you skim through that, you'll see several threads about
Main Trading having a good price on one of the SDS scanners, even to the point of getting the cost down not much more than the 436HP or 536HP. Right now, he dos not list either the SDS100 or SDS200 , so he may be put of stock at the moment. I've never purchased from him (he's in Texas, so I would get whacked with an 8.25% sales tax), but there have been a number of posts from members that did purchase from him, and were very pleased.
If you intend to scan from home (or another fixed location), it's possible that a 536HP, paired with a directional antenna (like a yagi) might work. Or maybe not. One downside of that is that you would likely miss some of the other systems you want that are in a different direction from where you have the antenna pointed.
The thing to remember is that simulcast is extremely location related. If you were very close (like a quarter mile) from one of the transmit sites, you might have no issues at all. (I doubt this is the case for you, since your 996P2 is struggling.) In some cases, moving the antenna a few feet in one direction or another may help. In other cases, something metallic (whether metal siding on your house, or foil backed insulation in your walls) may help if you can find a 'sweet spot'. I have seen some cases where using a metal baking pan, or cookie sheet, placed to one side of the scanner (presuming, of course, that you are using the antenna on the back of the set, not an external on your roof) can make the scanner work. There's no 'one thing does all' solution. There are things you can try, and if you're lucky, might work. But the only definite things that
will work is one of the SDS scanners, a Unication pager, the P25RX-II receiver, or using one of the SDR dongles along with software that can be downloaded and installed on your PC. The Unication & P25RX-II are not true scanners, They do handle simulcast, but are not scanners in that you can program from the keypad & get just about all of the systems in your area.