Preamplfier - any help with freq 452's and 457's for SoftEOT & SoftDPU?

[sd80mac]

Hi-

First of all, I'm deaf and I'm entering the Radio world first time so I'm pretty much having little knowledge with Radio stuffs.

I have Bearcat SR30C and will receive Bearcat BCD15X soon and Tram 1170.

I understand that 452's and 457's (only 6 frequencies all together) is Line Of Sight.

I am trying to increase the distance range of pick up. Someone recommended custom tuned preamplifiers from AR2.

I called AR2 and they said that their products are very wideband and can overload the receiver.


Any suggestion/advice on how I can improve the distance range? different amplifer or booster from other companies? The further it can pick up, the better for me, especially being deaf and this SoftEOT can help me with head up of coming up trains.

Thanks
Ken

 

[Awesomeman92]

Preamps alone will not gain you more range, they will only amplify signals the antenna can already get (along with noise). The best way to increase range is to increase antenna height. Antenna gain is important too: the over 6 dBi gain from that Tram should do nicely for you if you can get it high and on a good metal surface. I wouldn't put money into a preamp until you get everything and see how it works as it is, you may be surprised at what it can hear.

 

[prcguy]

A preamp right at the antenna with a band pass filter to protect it from overload can improve reception slightly. AR2 preamps are not very good and you can get better specs at a lower price elsewhere. The hurdle would be to find an appropriate band pass filter for 452 to 457MHz with sharp skirts either side of that, then I would recommend a MiniCircuits ZX60-P103 amplifier after the filter and about 10dB attenuation after the preamp depending on coax loss. You can power the preamp through the coax with two bias Tees or power inserters available cheap off eBay.

As mentioned, antenna height will also increase range and probably at a much lower cost. And finally, the Tram 1170 antenna is about 2dBd gain and not that good for base station use, their advertising is an outright lie. A better antenna will also increase range.

 

[sd80mac]

Thanks

Ill look into MiniCircuits.

And how would i get higher height from my car?? My vehicle is 2015 impala so rooftop isnt that high. Lol...

Yeah it will be mobile....

 

[prcguy]

You need a mobile tower, pull over on the hwy, crank up the tower, listen for awhile, crank it down and on you way. Honestly I didn't think this was for mobile use and a preamp will probably not improve things enough to be worth the expense and hassle.

Thanks

Ill look into MiniCircuits.

And how would i get higher height from my car?? My vehicle is 2015 impala so rooftop isnt that high. Lol...

Yeah it will be mobile....

 

[sd80mac]

Like this??

Ill keep eye for surplus auction

 

[N9CWF]

You didn't tell us the significance of your hearing loss. Total, partial, loss of high frequencies? That would help in understanding your needs.

There really isn’t an easy hardware/software solution to your situation.

EOT’s are very low power line of sight devices. hearing one will only tell you a train is in the area. It won’t tell you direction of travel, location, or even if the train is on the track you’re watching. EOTs transmit every 40 seconds.

SoftEOT is virtually useless; aside from the hassle of running a computer in your vehicle. SoftEOT, other than seeing a train’s brake pressure, offers little to no information.

DPUs aren’t worth the bother to monitor. They are only active when receiving signals from the lead locomotive. They are largely quiet.

A good scanner and antenna is all you need. Adding devices in your signal chain will only add to your expense, increase noise, possibly decrease sensitivity and give you little to no benefit at all.

Here’s my suggestion.

Program the 452.9375/457.9375 MHz frequency pair into your scanner, the EOT Device is on the higher frequency and the locomotive engine is on the lower. Set the screen’s backlight to come on only when it receives a signal.

Since EOT devices transmit at two watts, the transmission will travel about 3 to 5 miles. By setting your scanner to scan these EOT frequencies you will hear, or see (screen backlight), when a train approaches.

That’s your early warning system.

If your hearing is sufficient to allow you to hear the scanner audio then program the radio with the road channels for the railroads in your area. Defect detectors are a better indication of train activity than DPU. Detectors announce the speed, direction of travel, axle count and any hot wheels, dragging equipment etc… If you learn the traffic patterns of your local railroads and the locations of defect detectors you can often have a 10 to 15 minute heads up.

 

[sd80mac]

Yeah, when i mentioned that im using radio fir furst time... I figured that it would tell u that im total deaf.

So far, most of places, i get hot pop up in my laptop w 3 min or more advance. I dont need it to tell me direction or other info since im not moving. But in other few spot, i would see trains first b4 it pop up in my laptop.

Same id# popping up tell me that its in the yard. Right now i have 3 id # keepimg popping up. 4321, 37226 and 4418. And 4th one 5837.

I know 4418 is local. 2 other nbrs may be trains that are working in yard or stopped there. 5837 disappeared which tell me that it worked in yard (swapping the blocks of cars) and had left to west. Im in east side of yard.

all i need to see if# pop up. Then i know its coming.

if i do what u suggest w 160/161. Backlight will continue to come ona lot. It would pick up dispatchers, mow guys, local, hot box/dragging detector and train crew . It'll be hard for me to determine which one is one.

Ill try it but my SR30X bacight doesn't come on...

If DD/hot box have their own freq, it would help me, for sure....

Thanks for suggestion. Appreciated your reply

Ken

You didn't tell us the significance of your hearing loss. Total, partial, loss of high frequencies? That would help in understanding your needs.

There really isn’t an easy hardware/software solution to your situation.

EOT’s are very low power line of sight devices. hearing one will only tell you a train is in the area. It won’t tell you direction of travel, location, or even if the train is on the track you’re watching. EOTs transmit every 40 seconds.

SoftEOT is virtually useless; aside from the hassle of running a computer in your vehicle. SoftEOT, other than seeing a train’s brake pressure, offers little to no information.

DPUs aren’t worth the bother to monitor. They are only active when receiving signals from the lead locomotive. They are largely quiet.

A good scanner and antenna is all you need. Adding devices in your signal chain will only add to your expense, increase noise, possibly decrease sensitivity and give you little to no benefit at all.

Here’s my suggestion.

Program the 452.9375/457.9375 MHz frequency pair into your scanner, the EOT Device is on the higher frequency and the locomotive engine is on the lower. Set the screen’s backlight to come on only when it receives a signal.

Since EOT devices transmit at two watts, the transmission will travel about 3 to 5 miles. By setting your scanner to scan these EOT frequencies you will hear, or see (screen backlight), when a train approaches.

That’s your early warning system.

If your hearing is sufficient to allow you to hear the scanner audio then program the radio with the road channels for the railroads in your area. Defect detectors are a better indication of train activity than DPU. Detectors announce the speed, direction of travel, axle count and any hot wheels, dragging equipment etc… If you learn the traffic patterns of your local railroads and the locations of defect detectors you can often have a 10 to 15 minute heads up.

 

[tunnelmot]

Thinking WAY out of my league here, but I wonder if defect detectors were piped into a pc, would voice recognition software be feasable? Seeing as how detector messages are pretty monotone I would assume it would work.

 

[sd80mac]

Yes, I did tried that. Caption came out gibbish and not clear. Another issue is captions disappeared within 3 or 4 seconds. So if I'm not looking at screen, I would miss a lot of pop up captions.

Thinking WAY out of my league here, but I wonder if defect detectors were piped into a pc, would voice recognition software be feasable? Seeing as how detector messages are pretty monotone I would assume it would work.

 

[sd80mac]

A preamp right at the antenna with a band pass filter to protect it from overload can improve reception slightly. AR2 preamps are not very good and you can get better specs at a lower price elsewhere. The hurdle would be to find an appropriate band pass filter for 452 to 457MHz with sharp skirts either side of that, then I would recommend a MiniCircuits ZX60-P103 amplifier after the filter and about 10dB attenuation after the preamp depending on coax loss. You can power the preamp through the coax with two bias Tees or power inserters available cheap off eBay.

As mentioned, antenna height will also increase range and probably at a much lower cost. And finally, the Tram 1170 antenna is about 2dBd gain and not that good for base station use, their advertising is an outright lie. A better antenna will also increase range.

Hi PRCGUY. What antenna would u recommend for each - mobile and permanent?

I may set up few locations in future.

Hi N9CWF - same Q for u. Also any suggestions on good scanner?

Thanks.

 

[sd80mac]

A better antenna will also increase range.

What base antenna would you recommend?
One of these 450-460 MHZ fiberglasss antenna

450-470 MHz 9dBi Omni Antenna N female connector from L-com
FG4505 450-460 MHz 5dBd/7.15 dBi fiberglass Omni base station antenna
FG4507 450-460 MHz 7dBd/ 9.15 dBi fiberglass Omin base station antenna

or??? any other suggestion?

It will be permanetly placed on structure.

Thanks

 

[sd80mac]

For the updates with what I had done.

I had obtained BCT 15x and had done discrimination tap on this radio scanner. It's working well in both SoftEOT and SoftDPU. Actually SoftDPU went crazy whenever it's nearby. And it's usually the first one to pop up in laptop. SoftEOT does give me head up of oncoming train. Some locations , its 3-5 minutes and other locations give me more depending on surrendings. I'm satisfied with this.

I am considering placing few along the location, such as at one railway museum (further west), one location at west side of city and other one on east side of city, about 20 miles outside of city on each side. And one would be place further east. That should give me an idea of how many are coming.... that's why i'm looking into good reliable base antenna which will be place on highest point of structure. I would use my google remote to check out these locations.