Bought this pre-amp off eBay going to to be feeding a couple of radios

[crazyretrotech]

Bought this pre-amp off eBay claiming to be low noise at only 1 db. It is a Kitztech Broadband Low Noise Preamp with a 1 db noise figure of 40 Mhz TO 2000 Mhz, have to see how true that is? Seen a lot of fake antenna that are not close to tuned and literally a piece of wire shoved in a PVC tube, will do some tear down of those in the future, so people don't get ripped off on them. This pre-amp I am hopeful as they do make decent amplifiers for TV. Going to be feeding 2 scanner for now going into a MINI-CIRCUITS SPLITTER ZFSC-2-2+ 10-1000 MHz. Going to go on a outdoor antenna setting up over the weekend to replace my window mounted one I have now currently. Yes it can be DC feed thru Coax cable and don't need adapter, so going to keep near antenna in a water proof enclosure.

 

[prcguy]

Noise figure is only one of many important specs to look for. What's its 1dB compression point? What's its IP3 rating? How much gain does it have?

 

[crazyretrotech]

Noise figure is only one of many important specs to look for. What's its 1dB compression point? What's its IP3 rating? How much gain does it have?

Yep exactly, but no other specs where provided.

 

[crazyretrotech]

It claims 18.5 db gain. Will be testing it and also will do a tear down to see what they are using and datasheet specs on parts.

 

[w4amp]

It's a great pre amp, I have one in line now. But the little switching power supply destroys HF frequencies. I threw it in the trash and run the preamp off of a linear supply. I informed the seller on Ebay and never got a response.

 

[2IR473]

I bought a Kitztech preamp a couple of months ago, and bought a second one for my bank of old analog scanners, since it worked well for me. Each is feeding a Stridsberg 4 port multicoupler. Since I only use indoor antennas, these preamps work well for me, and are reasonably priced. My antennas are just 4’ telescoping whips from Amazon, that are attached directly to the input of the preamps.

I originally got one because I was just out of range of the nearest RCAG transmitter (26 miles away), to hear New York Center transmissions. I could barely hear NYC in the noise if I opened up the squelch. With the preamp, NYC comes in even at full squelch setting. Additionally, the preamps have enhanced my reception of all other traffic.

I live within 2 miles of a hospital with high power paging transmitters on it’s roof. I have always had intermod that requires the use of a Par Electronics 152mHz notch filter, and I run one of those on each of the outputs of the preamp, and I have no additional intermod with the preamps in line.

I also do not use the provided power supply, as I also found the wall wart created some RF hash, and the cord was not long enough for my particular installations. I simply replaced the power supplies and all is good. I understand Kitztech is selling the preamp, not the power supply, but it might be better to not include the supply, as I first thought the preamp was faulty because the RF hash was actually attenuating my reception, using the provided wall wart, until I tried another one.

 

[prcguy]

The Intermod filters go before any preamps as most preamps are more susceptible to IMD than the radio. If you were to use an antenna that is actually tuned to the aircraft bands you may not need the preamps. I've seen 10 to 20dB degradation using an antenna tuned for amateur or commercial bands for aircraft reception. A telecsoping whip, even when tuned to aircraft is about equal to a coat hanger with some coax attached. Going to an actual aircraft band antenna or Discone or similar can make a huge difference.

I bought a Kitztech preamp a couple of months ago, and bought a second one for my bank of old analog scanners, since it worked well for me. Each is feeding a Stridsberg 4 port multicoupler. Since I only use indoor antennas, these preamps work well for me, and are reasonably priced. My antennas are just 4’ telescoping whips from Amazon, that are attached directly to the input of the preamps.

I originally got one because I was just out of range of the nearest RCAG transmitter (26 miles away), to hear New York Center transmissions. I could barely hear NYC in the noise if I opened up the squelch. With the preamp, NYC comes in even at full squelch setting. Additionally, the preamps have enhanced my reception of all other traffic.

I live within 2 miles of a hospital with high power paging transmitters on it’s roof. I have always had intermod that requires the use of a Par Electronics 152mHz notch filter, and I run one of those on each of the outputs of the preamp, and I have no additional intermod with the preamps in line.

I also do not use the provided power supply, as I also found the wall wart created some RF hash, and the cord was not long enough for my particular installations. I simply replaced the power supplies and all is good. I understand Kitztech is selling the preamp, not the power supply, but it might be better to not include the supply, as I first thought the preamp was faulty because the RF hash was actually attenuating my reception, using the provided wall wart, until I tried another one.

 

[crazyretrotech]

Use a custom antenna for aircraft band and get 69 to 70 RSSI but use a refurbished Uniden 436HP, or receiver for that band. Don't need a pre-amp for that. Need the pre-amp for 700 Mhz to 800 Mhz bands. Going to be on a linear power supply. Did test the pre-amp yesterday on my temporary window antenna and yes switch mode adapter is junk. Did well on a old 12VDC linear adapter had laying around. So Pre-amp is pretty good. Will likely still do detail testing on it when

 

[crazyretrotech]

Have a separate custom antenna for air band and yes use the intermod filters before the pre-amp . Don't need pre-amp for that as get 60 to 70 RSSI on that band. Need it for mainly 700 Mhz and 800 Mhz band. I use a refurbished Uniden 436HP and receiver for that band. Tested the pre-amp last night on my temporary window outside antenna and found that that switch mode adapter is bad and put out noise, so switch it to a old linear 500ma adapter I had laying around and that pre-amp did great, I be doing more detail testing on bench once I clear off projects currently working on which repairing and aligning a Yaesu FT-2000 transceiver and do a tear down on that pre-amp later on.

 

[prcguy]

Do you have a dedicated antenna for the 700/800 bands or will you use a wideband antenna like a Discone? You can easily run into problems feeding a wide band preamp from a wide band antenna. If the preamp is only for 700/800 stuff you can get a MiniCircuits high pass filter on Ebay for under $20 that will pass 700MHz on up and filter out FM broadcast, VHF TV, pagers, etc, letting the preamp only see what you want to receive. Its good insurance even if you don't think you have an Intermod problem.

Use a custom antenna for aircraft band and get 69 to 70 RSSI but use a refurbished Uniden 436HP, or receiver for that band. Don't need a pre-amp for that. Need the pre-amp for 700 Mhz to 800 Mhz bands. Going to be on a linear power supply. Did test the pre-amp yesterday on my temporary window antenna and yes switch mode adapter is junk. Did well on a old 12VDC linear adapter had laying around. So Pre-amp is pretty good. Will likely still do detail testing on it when

 

[crazyretrotech]

I have a antenna tuned for 700/800 bands. A wideband pre-amp will overload the front end otherwise without the high pass filter. I have a separate antenna tuned for other stuff I use with a Uniden 436hp and AOR receiver with no pre-amp as does great without needed it.