EWR Feed to be "Pre-Amped"

[jkaplan]

All,
We will be installing a pre-amp on our EWR feed late next week.  This should help us hear more of the aircraft on the ground.

-Jonathan

[KSYR-pjr]

Could you provide some more details about "pre-amping?" 

I run the Syracuse, NY, feed and am just far enough away that I do not pick up most ground-based aircraft.  I am curious if what you are doing will help in my case.

[jkaplan]

Hi Peter,

I am a newbie myself, but have been learning alot from Dave and Sean.

My understanding is that a pre-amp (which is connected between the antenna and the scanner) boosts the gain on certain target frequencies.  In my case, I ordered one that boosts 118-137. 

Sean sent me the link to the supplier: http://www.advancedreceiver.com/page3.html

...and I ordered one for EWR this morning.

[jkaplan]

...so to actually answer your question...

I am fairly sure that the preamp will help because when I open the squelch up a bit on my scanner, I can hear the ground aircraft in the background.  Since the pre-amp is focused on a specific frequency range, it should be very helpful.

If, however, you cannot hear the ground aircraft when you open your squelch, then I would suggest making sure the antenna is as high up a possible, and is free of obstructions toward the direction of the tower.

Beyond that, someone who actually knows about radio reception should be contacted!!!!

[KSYR-pjr]

If, however, you cannot hear the ground aircraft when you open your squelch, then I would suggest making sure the antenna is as high up a possible, and is free of obstructions toward the direction of the tower.

In the case of my feed, I am about 8-9 nm away from the airport and there is a hill between my house and the airport that prevents line of sight to the field.  I have the antenna mounted outside in the highest corner of my house, about 35 feet up, and I am using the very thick coax cable from the antenna to the scanner.  My feed can pick up larger aircraft on the ground (UPS cargo B757s and FedEx A340s, and most of the JetBlue A320s - we are a light-to-moderately busy class C airport, served mostly by regional jets) and occasionally, which seems due to weather conditions, I can weakly pick up small GA aircraft.  However, it is inconsistant enough that I don't bother to scan the ground frequency.

It looks like this preamp, especially at the frequencies you custom-ordered, would be beneficial to most feeds not located on airport property, as there is always the case of the far-away aircraft.

Which of the custom pre-amps did you order, the narrow tune or the broad tune?  (And what is the difference between the two?)  Also, after a quick read of the web link you provided, it looks like the preferred location for this pre-amp is actually up at the antenna.  How is the pre-amp powered?  An internal battery or external A/C power?

When it comes to radio reception, I too am a newbie, so welcome to the club.   

[jkaplan]

Sean told me:
"You'll have to order a "Special Frequency Range" for 118-137MHz.  Specifically the model you want is "P118-137VDG"

It sounds like this would apply for most feeders, but I would suggest verifying with Sean first!!!!

[dave]

Which of the custom pre-amps did you order, the narrow tune or the broad tune?  (And what is the difference between the two?)  Also, after a quick read of the web link you provided, it looks like the preferred location for this pre-amp is actually up at the antenna.  How is the pre-amp powered?  An internal battery or external A/C power?

When it comes to radio reception, I too am a newbie, so welcome to the club.   

Reception in the VHF (civilian) airband is limited primarily by man-made noise, so mounting the preamp at the antenna does very little to help.  That being said, it certainly won't hurt things.  The only downsides are: 1) exposure to the elements (the ARR preamps are not weatherproof) and 2) the need to power the preamp correctly, which is done through what we call a bias tee.  A bias tee allows for DC power to be sent to the remote preamp without damaging your receiver.  It uses an inductor to pass DC power and capacitors to block the DC power and couple signals from the antenna to the feedline and from the preamp to the receiver.   

I would go with a low-loss feedline, such as you are already using, and put the preamp inside.

The other downside is that you may start getting interference on your feed if the preamp gets overloaded by a strong FM radio station or a strong land mobile radio transmitter in the VHF band.  NOAA weather may also be a problem, if the transmitter is close to you.  I highly recommend an FM trap filter (Radio Shack sells a cheap one) as a precaution or if you start to experience FM radio station trouble.

Another item that will help is an AB125 bandpass filter.  Google around for it - there are a couple of sources out there.

Finally, the GaAsFET-based preamp with the part you listed has about 24dB of gain.  That may overload your scanner and cause interference to be generated inside the scanner.  So you may need a BNC attenuator (sometimes called a pad) ot drop the signal level down.  Unfortunately, the preamp is fixed gain and can't be adjusted for variable gain.

Hope this helps.

Dave