need help please

[MichaelGreer]

i have a galaxy 99 that works great and i am very happy with it , yesterday had the opportunity to buy a palomar 450 elite linear , what needs to be done to my radio before i can hook to linear , please be specific as i am no radio head , just afraid i might burn something up , please help

 

[222DBFL]

As long as the radio hasn't been peaked and tweaked, it should have variable rf power. Set the dead key on am to about 2 watts. If the radio is stock it will be fine with that amp.

 

[MichaelGreer]

As long as the radio hasn't been peaked and tweaked, it should have variable rf power. Set the dead key on am to about 2 watts. If the radio is stock it will be fine with that amp.

 

[MichaelGreer]

im pretty sure it has been tuned and peaked , when i talk the power meter reads about 45 w , like i said , i dont know beans about radios , and i dont want to damage what ive paid good money for , if it has been tuned and peaked , what are my options at this point ?

 

[M0GVZ]

I'd be more worried about what needs to be done to your antenna system and if mobile, both your antenna system and the power supply.

If you're running it mobile you want to be going for a fixed mount and you want to be using RG8, not RG58 coax. You also need to be using a heavy duty cable for power from the battery - this sucker and the radio are going to be drawing 60+ amps on peak.

Base installation wants to be RG213 as a minimum, you want to be putting a 1:1 RF Choke at the antenna feed point or as close as possible.

 

[222DBFL]

Totally agree there M0GVZ. But also I don't know if I would put that much pep wattage into that amp. Too much. Needs to get down to about 20-30 watts max pep on the radio. Dead key set at about 2 watts, or about 80 watts carrier from the amp on high gear. If that amp has 4 sd1446's in it, that is what I would do. They are not a true high drive amp and don't require a bunch of pep power to make the transistors work. Get your radios power backed down to about 20-25 watts max and then use the amp. I would start with a 1 watt carrier and move the rf power up until the 80 watt carrier is achieved with the amp on. Leave that setting there on the radio. A decent watt meter will be needed and like stated, is this a base or mobile setup? If mobile I would use #4awg wire from the amp to the battery and a #4awg ground as well unless the amp came with at least #6awg. Make the ground as short as possible and use a good frame bolt. Your antenna system needs to be up to snuff before any of this can happen, so more info would be nice, but above is just my experience with these amps. Like stated above more info would help as well.

 

[fourstringburn]

If you're running it mobile you want to be going for a fixed mount and you want to be using RG8,

Don't you mean RG8X for mobile?

im pretty sure it has been tuned and peaked , when i talk the power meter reads about 45 w ,

Peaked and tuned is fine. When you talk into the radio on AM mode and you see 45 watts, that is your peak power. When you dead key the radio( key mic without talking) set that wattage with your power meter to 3 watts using your RF power knob. Your peak power might drop some but that's OK so don't get hung up on a couple of watts lost.

Your RF power knob controls how much dead-key you have. This is what gives your radio "swing" which amps need to really drive it. Swing is the ratio between deadkey and peak power. In your case, your radio set to 3 watts will swing up to 45 watts when speaking into it. That is a lot of swing but quite alright with the CB crowd.

The more swing from your radio will give your amp the "big audio" CBers are after. Too much dead-key only causes excessive heat in both your radio and amp and can over-saturate your amp leading to transistor failures.

Think of it like turning the idle up on your car, you won't get any more speed or power, but you will waste more gas and gain nothing.

Take M0GVZ 's advice and concentrate on your antenna system and you have an adequate power supply.

Big power means nothing without a good antenna system that is properly matched and installed. A unmatched antenna could damage your amp as well.

 

[MichaelGreer]

I'd be more worried about what needs to be done to your antenna system and if mobile, both your antenna system and the power supply.

If you're running it mobile you want to be going for a fixed mount and you want to be using RG8, not RG58 coax. You also need to be using a heavy duty cable for power from the battery - this sucker and the radio are going to be drawing 60+ amps on peak.

Base installation wants to be RG213 as a minimum, you want to be putting a 1:1 RF Choke at the antenna feed point or as close as possible.

yes, sorry, this is a mobile application , my antenna system is good , swrs set at 1.2 /1.5 , not sure about the size of coaxial cable , so if i get a larger coaxial cable will i have to have my antenna tuned again , and yes it is fixed mounted , and if at full power drawing 60 plus amps will this screw up my altenator , and yes im going to run full sized wires to battery , what about a fuse , what size and where would i get a inline fuse box for this size wire ,so your saying to turn down rf gain to 2 w on dead key then turn amp on

 

[fourstringburn]

That's another point, you need a big enough alternator to run your vehicle and your amp. Your stock car alternator was designed to run your vehicles electrical components with amperage to spare.

If you have an alternator less than 100 amps, I would get a higher amperage alternator.

Your coax cable should have some printing on every foot of cable or so telling you what type of cable it is. If it a clear cable, it is kind of hard to read but look carefully and it should be there.

RG8X is good enough for what your are using for. If it is RG58 I would replace it.

Get an minimum 100 amp fuse and fuse both positive and negative leads ( negative leads carry voltage too) and go direct to the battery with both leads. This can prevent ground loops from appearing which can cause havoc on your radio and vehicles electronics. I experienced ground loops before with one of my mobile installs and this cured it.

Car stereo dealers sell the inline plastic bubble fuses for wire gauges up to 2AWG and I have seen them at Autozone too. Number 4 AWG is more than adequate for your mobile install since I doubt it will be more than 10 feet.

 

[M0GVZ]

yes, sorry, this is a mobile application , my antenna system is good , swrs set at 1.2 /1.5 , not sure about the size of coaxial cable , so if i get a larger coaxial cable will i have to have my antenna tuned again , and yes it is fixed mounted , and if at full power drawing 60 plus amps will this screw up my altenator , and yes im going to run full sized wires to battery , what about a fuse , what size and where would i get a inline fuse box for this size wire ,so your saying to turn down rf gain to 2 w on dead key then turn amp on

Yeah I'm afraid that SWR means absolutely nothing. Fourstringburn was right, I meant RG8X. You need to do that because the amp running at its max output is right on the very edge of what RG58 is safe for. You won't need to retune your antenna if you change the coax.

I'm glad you've got a fixed mount. Magmounts can only provide enough capacitive coupling for a couple of hundred watts. Above that you start having all kinds of issues and at the max output of the amp you could see paint burn.

In regards to the current, 100W amateur radio transceivers draw 23A. A Kenwood TS480HX which is a 200W radio draws 41A. Basically as a rule of thumb you're looking around 20A per 100W plus a couple of amps for the radio. So run the amp at 400W and you're wanting 80A for the amp plus 3-4A for the radio. I would not run it that high though. To receiving stations there is very little difference between 200W and 400W even though it sounds like there's a massive difference in power. Running 200W would mean you have less problems from inadequate antenna grounding, you don't have to run as much power to the amp and rig and best of all, because you're not driving the amp hard you'll have a very clean signal.

 

[MichaelGreer]

I'd be more worried about what needs to be done to your antenna system and if mobile, both your antenna system and the power supply.

If you're running it mobile you want to be going for a fixed mount and you want to be using RG8, not RG58 coax. You also need to be using a heavy duty cable for power from the battery - this sucker and the radio are going to be drawing 60+ amps on peak.

Base installation wants to be RG213 as a minimum, you want to be putting a 1:1 RF Choke at the antenna feed point or as close as possible.

Yeah I'm afraid that SWR means absolutely nothing. Fourstringburn was right, I meant RG8X. You need to do that because the amp running at its max output is right on the very edge of what RG58 is safe for. You won't need to retune your antenna if you change the coax.

I'm glad you've got a fixed mount. Magmounts can only provide enough capacitive coupling for a couple of hundred watts. Above that you start having all kinds of issues and at the max output of the amp you could see paint burn.

In regards to the current, 100W amateur radio transceivers draw 23A. A Kenwood TS480HX which is a 200W radio draws 41A. Basically as a rule of thumb you're looking around 20A per 100W plus a couple of amps for the radio. So run the amp at 400W and you're wanting 80A for the amp plus 3-4A for the radio. I would not run it that high though. To receiving stations there is very little difference between 200W and 400W even though it sounds like there's a massive difference in power. Running 200W would mean you have less problems from inadequate antenna grounding, you don't have to run as much power to the amp and rig and best of all, because you're not driving the amp hard you'll have a very clean signal.

Ok , hey thanks for all the information so far , let me see if I've got it right , went and bought 8AWG wire ( Home Depot ) to run from battery terminals to bubble fuse holders ( Radio Shack ) , biggest fuses i could find were 60 amp ( Auto Zone ) , check coaxial cable if its rg58x replace it with rg8x , with amp off turn rf gain down to 2 watt dead key , turn amp on to no more than 200 w for a good clean signal , anything else , and let me say thanks for your help again , means a lot , thanks

 

[MichaelGreer]

That's another point, you need a big enough alternator to run your vehicle and your amp. Your stock car alternator was designed to run your vehicles electrical components with amperage to spare.

If you have an alternator less than 100 amps, I would get a higher amperage alternator.

Your coax cable should have some printing on every foot of cable or so telling you what type of cable it is. If it a clear cable, it is kind of hard to read but look carefully and it should be there.

RG8X is good enough for what your are using for. If it is RG58 I would replace it.

Get an minimum 100 amp fuse and fuse both positive and negative leads ( negative leads carry voltage too) and go direct to the battery with both leads. This can prevent ground loops from appearing which can cause havoc on your radio and vehicles electronics. I experienced ground loops before with one of my mobile installs and this cured it.

Car stereo dealers sell the inline plastic bubble fuses for wire gauges up to 2AWG and I have seen them at Autozone too. Number 4 AWG is more than adequate for your mobile install since I doubt it will be more than 10 feet.

hey thanks for your help , i hope this is ok took amp to home depot matched wire size to 8AWG , this is what I'm using from the battery to bubble fuses , largest fuse i could find was 60 amp , not sure about coaxial cable yet , will know tomorrow , i have another question though , both the radio and amp have labels on the back saying antenna and transmit , can you give me an installation sequence , know what i mean

 

[fourstringburn]

the 60 amp fuse will work for now but try to get a 100 amp in there when you can. The 8 gauge is fine as long as your not much over 10 ft.

Don't know about those labels. I have always seen on amps, Radio and Antenna. Simple enough, Radio coax jumper out to "Radio " on amp, then antenna coax connector to "Antenna" on amp.

Does your amp have a preamp? a safe way to make sure your connections are correct is after connecting coax cables, power the amp on BUT DO NOT TRANSMIT, switch on the preamp and you should hear the receive audio increase on your radio as well as see your signal strength meter rise. if not, reverse the connections and try again.

 

[fourstringburn]

I couldn't find no spec's on that amp but based on a similar Texas star with 4-2290 transistors, the peak amperage is 40 amps and in the real world it will probably peak less than 35 amps, so that 60 amp fuse is fine.

Most fuses are double the max amperage rating to allow for peaks but still blow with large spikes.

 

[MichaelGreer]

I couldn't find no spec's on that amp but based on a similar Texas star with 4-2290 transistors, the peak amperage is 40 amps and in the real world it will probably peak less than 35 amps, so that 60 amp fuse is fine.

Most fuses are double the max amperage rating to allow for peaks but still blow with large spikes.

Hey sorry to leave you hanging , my coaxial cable is RG8X , so I'm good there , but I'm having another problem , my RFgain knob will not lower my dead key to 2w , as I turn the knob it stays at 7.5 to 8 w , does this mean someone has tweaked the radio , or am I doing something wrong , it's an older model Galaxy dx99v , I was told these are really good radios