preamp

[FCVPI99]

do preamps really work? i have a couple VHF FD towers i listen to and its right on the edge some times i get it great sometimes all i hear is a static machine gun sound (its NOT digital) the machine gun is like a wave sometimes its deep some times its shallow and i can make out the words some times not there at all .... so if i get a preamp that cover the VHF range will it "suck" the signal in better? is it better to buy a hole built or mass produced one?? i never dealt with preamps as i never needed them before but i live in the boone docks now i do have to say i have delt with problems i have never had to deal with before in my 30+ years of scanning .. starting to hate the boone docks ..

 

[Ubbe]

Most preamps works as they have a lower noise figure than a scanner. If you use a preamp that has a NF noise figure of 1dB or lower to amplify the signal and then attenuate it to a resulting 3-6dB of total gain it will overcome the bad noise figure, and any coax loss, in the scanner and improve weak signal reception. But if you also have powerful transmitters that the preamp amplify then the scanner could overload and reduce its gain resulting in a worse signal than without the preamp.

Carefully adjusting the attenuation level, using a variable attenuator, and perhaps using filters and as it is the sum of all signals that are important it could even help using a FM broadcast filter, you listen to a weak signal and try to get it as clear as possible.

At my weak signal location I even see improvement using cheap $5 inline amplifiers for sat dishes that has 3dB noise figures.

If you hear machine gun type of sounds then to me it sounds as you have interferences from other frequencies that might get worse with an amplifier and you instead need more filtering or a better receiver.

Those PGA103+ based amplifiers are very costeffective and cheap so try one of those, $20-$30, and preferably a variable attenuator and suitable pigtail coaxes.

/Ubbe

 

[FCVPI99]

Most preamps works as they have a lower noise figure than a scanner. If you use a preamp that has a NF noise figure of 1dB or lower to amplify the signal and then attenuate it to a resulting 3-6dB of total gain it will overcome the bad noise figure, and any coax loss, in the scanner and improve weak signal reception. But if you also have powerful transmitters that the preamp amplify then the scanner could overload and reduce its gain resulting in a worse signal than without the preamp.

Carefully adjusting the attenuation level, using a variable attenuator, and perhaps using filters and as it is the sum of all signals that are important it could even help using a FM broadcast filter, you listen to a weak signal and try to get it as clear as possible.

At my weak signal location I even see improvement using cheap $5 inline amplifiers for sat dishes that has 3dB noise figures.

If you hear machine gun type of sounds then to me it sounds as you have interferences from other frequencies that might get worse with an amplifier and you instead need more filtering or a better receiver.

Those PGA103+ based amplifiers are very costeffective and cheap so try one of those, $20-$30, and preferably a variable attenuator and suitable pigtail coaxes.

/Ubbe

i saw that one but its not BNC so i would be adding loss to remove loss .. i was looking at that moonraker M100

 

[Ubbe]

i saw that one but its not BNC so i would be adding loss to remove loss .. i was looking at that moonraker M100

You connect between devices using pigtail coax with the correct connectors at each end, no extra loss. Connectors do not add any loss that you can measure. I do not recommend M100, it's not up to todays standards.

/Ubbe

 

[prcguy]

i saw that one but its not BNC so i would be adding loss to remove loss .. i was looking at that moonraker M100

There is not enough loss through connectors to worry about, usually on the order of .1dB for a pair or .05dB each through 1GHz for type N and a little more for others.

 

[FCVPI99]

You connect between devices using pigtail coax with the correct connectors at each end, no extra loss. Connectors do not add any loss that you can measure. I do not recommend M100, it's not up to todays standards.

/Ubbe

what do you mean today's standards? im using it for VHF only i dont think its really ever changed

 

[rf_patriot200]

do preamps really work? i have a couple VHF FD towers i listen to and its right on the edge some times i get it great sometimes all i hear is a static machine gun sound (its NOT digital) the machine gun is like a wave sometimes its deep some times its shallow and i can make out the words some times not there at all .... so if i get a preamp that cover the VHF range will it "suck" the signal in better? is it better to buy a hole built or mass produced one?? i never dealt with preamps as i never needed them before but i live in the boone docks now i do have to say i have delt with problems i have never had to deal with before in my 30+ years of scanning .. starting to hate the boone docks ..

I use the Stridsberg MCA204MIL, which has only a small 10db distribution amp in the circuit, and it makes a noticeable increase in signals across the spectrum from 40mhz. up to 1ghz. It has Bnc outputs as well.

 

[Ubbe]

what do you mean today's standards? im using it for VHF only i dont think its really ever changed

Yes, that's my point, it's a 30 year old design that cannot compete with a modern amp using modern components.

/Ubbe

 

[FCVPI99]

Yes, that's my point, it's a 30 year old design that cannot compete with a modern amp using modern components.

/Ubbe

i tend to find old stuff is better then the new stuff

 

[dlwtrunked]

i tend to find old stuff is better then the new stuff

Then you are not looking at the right new stuff.

 

[FCVPI99]

Then you are not looking at the right new stuff.

or im looking at the better older stuff cuz all the newer stuff is garbage from China

 

[rf_patriot200]

or im looking at the better older stuff cuz all the newer stuff is garbage from China

Expand your horizons a bit, it's easy for newer innovating tech to escape us because we get tunnel vision into thinking we've seen it all, had it all when in fact we miss products which could actually be a gem and just exactly what we've been looking for.

 

[ynot58]

do preamps really work? i have a couple VHF FD towers i listen to and its right on the edge some times i get it great sometimes all i hear is a static machine gun sound (its NOT digital) the machine gun is like a wave sometimes its deep some times its shallow and i can make out the words some times not there at all .... so if i get a preamp that cover the VHF range will it "suck" the signal in better? is it better to buy a hole built or mass produced one?? i never dealt with preamps as i never needed them before but i live in the boone docks now i do have to say i have delt with problems i have never had to deal with before in my 30+ years of scanning .. starting to hate the boone docks ..

I have a jim m75 amp and love it. Yes it brings static with distant frequencies coming in but you can at least hear farther. Excellent on hearing more distant digital, dmr, nxdn etc. I get stuff i couldn't before because 2nd floor apartment no static with distant digital but again who cares about static if it helps bring a signal in. I'm 66 and always bought what i wanted regardless of reviews and never had a problem in my life. Example (electric razor) tons of reviews not one was good but got it and it is the best i ever owned. The amp is nice to have. Sometimes i have to turn dial down for some things and up for others. Just have to play with it. It works great for me.

 

[ynot58]

do preamps really work? i have a couple VHF FD towers i listen to and its right on the edge some times i get it great sometimes all i hear is a static machine gun sound (its NOT digital) the machine gun is like a wave sometimes its deep some times its shallow and i can make out the words some times not there at all .... so if i get a preamp that cover the VHF range will it "suck" the signal in better? is it better to buy a hole built or mass produced one?? i never dealt with preamps as i never needed them before but i live in the boone docks now i do have to say i have delt with problems i have never had to deal with before in my 30+ years of scanning .. starting to hate the boone docks ..

I have a jim m75 amp and love it. Yes it brings static with distant frequencies coming in but you can at least hear farther. Excellent on hearing more distant digital, dmr, nxdn etc. I get stuff i couldn't before because 2nd floor apartment no static with distant digital but again who cares about static if it helps bring a signal in. I'm 66 and always bought what i wanted regardless of reviews and never had a problem in my life. Example (electric razor) tons of reviews not one was good but got it and it is the best i ever owned. The amp is nice to have. Sometimes i have to turn dial down for some things and up for others. Just have to play with it. It works great for me.

Also with jim m75 pre amp get ac adapter saves money on batteries when on base station. Same adapter for 536hps and later unidens.

 

[FCVPI99]

Also with jim m75 pre amp get ac adapter saves money on batteries when on base station. Same adapter for 536hps and later unidens.

ever hear of moonraker?? thats the one i was looking at

 

[ynot58]

Yes same thing but these are built better jim m75 is way to go. Built better than others