Hi... The reason you are able to hear those MARCS sites is because they are not digital simulcast as is the Belmont Co system...
For example I can actually see a tower of Belmont Co from my location but when conditions are wrong, I cannot reliably receive anything from the Belmont Co System, just garbled bits and pieces and I'm talking less than 3 air miles.... When conditions are right I can hear all Belmont Co fire traffic perfectly fine... If you are not high upon a hill out there then your chances of receiving anything from that system are slim to none but the fact that you can hear Ohio MARCS tells me that is not the case... If you do indeed have a good line of sight to the west/northwest then an 800mhz tuned antenna pointed toward the nearest tower might be your best chance for being able to monitor Belmont County Fire during times of favorable conditions.....
I did a bit of research...
The closest Belmont Co tower to you is actually located in Marshall Co just off of Roberts Ridge near WV Rt 2.... The intersection of US Rt 250 and Middle Grave Creek Rd is very near to Beelers Station so I used that as my reference point since I dont know your exact location...... According to Google Earth that is a line of sight distance of only 10.21 Miles- well within normal reception range unless you are down in a creek bottom or otherwise located in a valley..... This "Moundsville" Tower is just north of being due west of the aforementioned intersection (at a heading of 280°) however the problem is that only 9.33 miles past that tower is their "Alledonia" Tower (19.47 air miles from Middle Grave & 250) The fact that these two towers are practically in a direct path from your location means that if you had an antenna pointed at Moundsville you would likely get some signal from Alledonia which would most likely cause simulcast distortion.... However, if you were to point your antenna at a 325° heading you would be aiming directly at their "Kirkwood" Tower which is a mere 14.81 miles from that intersection on US250... There might be a better chance to avoid simulcast distortion by aiming at Kirkwood as there are no other Belmont Co System tower sites in that general direction from you......
Here is my first suggestion to you:
Albeit it is much easier to do this with a portable radio having batteries than it is using a desktop radio with a long extension cord, you might want to manually tune your radio to 853.7 (press TUNE>853.7>ENT)and very slowly move it around different locations in your place watching the display at all times to see if your Whistler can pick up any signal at all which will help you gauge how successful your efforts may be... Radio waves can be really funny in that you can get no signal in one place and then move your radio five inches to the left and get a good enough signal for successful digital decode... At any rate if you were to do this, and you do get any signal, your radio's display will show you what % decode you are getting and if it' goes above a certain threshold you will actually hear the CC buzzsaw audio... You did not specify what actual MARCS sites you were hearing but if you are hearing the "Kirkwood" MARCS Site then I bet you will get at least something from Belmont Co (although now with MARCS IP we are talking 700 MHz vs. 800 MHz and I'm not an expert to know the difference in the two).....
For example in my house I really wanted to pick up the MARCS "Adena" tower but could get nothing at all so took my 106 portable all over the entire house and had success... I found that the only place in the entire house where I can receive it is in the 2nd floor bathroom sitting on the top of the bottom window sash just to the right of the window's lock.... I tried the attic, the other rooms on all floors, other windows, the roof even and that one spot is the only place I can get a continuous full decode on most days.........
Again, some days will be better or worse than others and if you do get a good decode at some point, atmospheric conditions will have the final say and that will be the deciding factor as to when you can and when you can not hear the system........ Without having an actual radio that is tuned to the Belmont Co Radio system anyone between Limestone and Beelers Station will probably never be able to receive that system 100% of the time no matter how much they spend in equipment... It sucks but this is the digital age in which we now live,,,
Edit: I reread your post where you said you were seeing 691-- You are looking at the wrong number, the system ID will be on the next screen right after the letters "SYS"and it will say 690... What you are seeing is the number right after the signal decode%
(on my1065 display it says: " 99% N691 W: BEE00 "
which I have no idea what any of that that means except for the decode percentage which is the thing you need to be looking at... and... for way better results manually tune in the frequency like I described above instead of scanning while you test signal.....
Ok I'm done talking your ear off now,,,Hope this helps a bit... If you need any other help I'd be glad to...
Good Luck.....