Comp. Guys. Sky's the Limit Guys. Question??

[yota167]

How to Keydowns work? The multiple antennas set in a line front to back are for "aiming" your signal in one specific direction? I'm not too proud to ask. I really am confused as to what it is exactly determines a winner of a keydown one truck vs the other. Is field strength meter used to determine winner? Someone please fill me in. I've been watching some SICK videos of big gnarly suburbans w/ huge antennas, tons of alts, and crazy rpms. It just got me thinking and I realized I have NO IDEA how they determine a keydown winner.

[626]

Yota,
*note the following is highly simplified. keydown/ comp guys take this stuff real seriously

The winner of the keydown is usually the one that shows up on the gate. Often two vehicles are facing the same direction and both key at the same time a third radio records the gate and a judge determines who was heard.

Keydown classes are seperated by amp size, whether you volt your amp, and antenna set ups. In keydowns a 1x2 is a 2 pill and a 2x4 is a 4 pill.

Most of the key set ups that run multiple antennas run on the same principle as a yagi...

There is a radiator or (hot) antenna behind it is a reflecting antenna and in front of it are multiple directors. Usually the reflector is longer than the hot antenna and the directors are shorter. This serves to focus the RF radiation in a specific direction.

My knowledge on this is second hand. Im not into keydowns because the gain you get on your antenna setup is totally directional. A normal mobile is MOSTLY omnidirectional compared to these specialized keydown rigs. The trick would be to get a totally drive around mobile that is a base killer. That would be true freedom of speech. LOL

626

[the_junkie]

Gunny pretty much hit the nail on the head...I'm so proud haha

a lot of times the watergate will come back and sound like a mess, so the gate station has to know what to listen for. Usually the 2 keyers are saying different things, and have a preference. I prefer to say "RELAY" because of the pitch and lobes. Others say 1, 3, 5, 9, worldwide...you get the point.

I got a couple fight tapes, lemme go find them...

[yota167]

Gunny pretty much hit the nail on the head...I'm so proud haha

a lot of times the watergate will come back and sound like a mess, so the gate station has to know what to listen for. Usually the 2 keyers are saying different things, and have a preference. I prefer to say "RELAY" because of the pitch and lobes. Others say 1, 3, 5, 9, worldwide...you get the point.

I got a couple fight tapes, lemme go find them...

Alright Gunny and The Junkie. I understand now. It's all about who can "stomp" the other tx and still be heard. Is the rx'ing radio off really far in the distance or really close? I'm still trying to get a grip on the layout of a KeyDown.
Thanks for shedding some light guys.

[the_junkie]

The gate station is usually somewhere between 15 and 40 miles.

I know the jacksonville break was about 20 miles, and lagrange was about 40, based on what i was told

a lot of local sterrt fights are just to whatever base will answer their phone, or who is on the band at taht time, so it could be 6 miles, it could e 60...

the street fights are more spur-of-the-moment and arent usually organized. I was going to go to one tonight, but decided to wait till next weekend when I can dress out the 5 antenna system and take my 4 pill to run with them 16 pill boys

[the_junkie]

Yota,
*note the following is highly simplified. keydown/ comp guys take this stuff real seriously

The winner of the keydown is usually the one that shows up on the gate. Often two vehicles are facing the same direction and both key at the same time a third radio records the gate and a judge determines who was heard.

Keydown classes are seperated by amp size, whether you volt your amp, and antenna set ups. In keydowns a 1x2 is a 2 pill and a 2x4 is a 4 pill.

Most of the key set ups that run multiple antennas run on the same principle as a yagi...

There is a radiator or (hot) antenna behind it is a reflecting antenna and in front of it are multiple directors. Usually the reflector is longer than the hot antenna and the directors are shorter. This serves to focus the RF radiation in a specific direction.

My knowledge on this is second hand. Im not into keydowns because the gain you get on your antenna setup is totally directional. A normal mobile is MOSTLY omnidirectional compared to these specialized keydown rigs. The trick would be to get a totally drive around mobile that is a base killer. That would be true freedom of speech. LOL

626

i was looking back through this post, and the area that i bolded i wanted to point something out.

The first directer is usually the same length/slightly shorter than the hot antenna, HOWEVER, your last to directors are somewhere around 16 feet. I will be tuning my 5 antenna system this sunday, so i will post pics after that. NOTE: no, i will not give out measurements...don't ask

If you are planning on a multiple antenna array, there is some good info at http://www.skater229.com/55antennamagic.html

this info came straight from 55, and i am using info from this site and a couple of the guys from his camp are helping me out with my setup.

I run a bounceback with 2 55-r4 coil antennas. In my opinion, they are the best coils on the market. I am running them in a bounceback configuration, and I am putting the HURT on some bigger boys. i took a 1x4 and keyed on an 8 pill. he made the tape, but it was "relay relay relay" on top. He was running a back hot, front director setup. Although his antenna system does make him slightly directional, the db gain from that setup isn't worth the time and effort to set it up.

His setup generates 1-2 db gain, where as my bounceback gives me somewhere in the range of 2-3 S-UNITS of forward gain. My backdoor has almost nothing coming out of it on a field strength meter, and most of the signal is shot to the front. HOWEVER, when running my 1x4, i can talk out of my backdoor, but not near as good as if you are in front of me. If you are considering a comp-style setup, I would reccomend starting with a good bounceback at 86" spacing (center of mount to center of mount) as this allows you to expand into a 4,5, or more antenna array, without drilling more holes in your truck.

[wrong way]

OK first off thank you Yota for bringing this up because I was told that your radio is most sensative when it is keyed and I have wandered what to do if I ever wanted to key with someone how far apart should we be?? In a field or what? I mean should the two mobles be a football field apart to prevent around 1000w of pep from damaging anything because when I get close to some of my buddies we turn the boxes off even passing eachother on the highways things start geting crunchie and scare me. main Question here is how do you prevent "BIG RADIO DAMAGE" Thanks Wrong Way

[the_junkie]

OK first off thank you Yota for bringing this up because I was told that your radio is most sensative when it is keyed and I have wandered what to do if I ever wanted to key with someone how far apart should we be?? In a field or what? I mean should the two mobles be a football field apart to prevent around 1000w of pep from damaging anything because when I get close to some of my buddies we turn the boxes off even passing eachother on the highways things start geting crunchie and scare me. main Question here is how do you prevent "BIG RADIO DAMAGE" Thanks Wrong Way

usually you are 20 ft - 30 ft apart. you won't experience damage as long as you both get off the key at the same time. It is just a risk u run. I know a guy who blew all his boxes, 2,4,6,8 at the line...that's a lot of money, but you gotta pay the cost to be the boss. A lot of these big heavy hitters are bringing 3 and 4 boxes with them to the breaks for backups...in ALL classes...

[yota167]

OK first off thank you Yota for bringing this up because I was told that your radio is most sensative when it is keyed and I have wandered what to do if I ever wanted to key with someone how far apart should we be?? In a field or what? I mean should the two mobles be a football field apart to prevent around 1000w of pep from damaging anything because when I get close to some of my buddies we turn the boxes off even passing eachother on the highways things start geting crunchie and scare me. main Question here is how do you prevent "BIG RADIO DAMAGE" Thanks Wrong Way

usually you are 20 ft - 30 ft apart. you won't experience damage as long as you both get off the key at the same time. It is just a risk u run. I know a guy who blew all his boxes, 2,4,6,8 at the line...that's a lot of money, but you gotta pay the cost to be the boss. A lot of these big heavy hitters are bringing 3 and 4 boxes with them to the breaks for backups...in ALL classes...

So what I gather from this is:

So long as you have someone signaling when to keydown and then signaling when to let off the key, the radios rx will not pickup all that rf correct? This in turn keeps from destroying eachother's setups....at least most of the time I would hope!

To me this whole "keydown" comp stuff is a big mystery.

[yota167]

OK first off thank you Yota for bringing this up because I was told that your radio is most sensative when it is keyed and I have wandered what to do if I ever wanted to key with someone how far apart should we be?? In a field or what? I mean should the two mobles be a football field apart to prevent around 1000w of pep from damaging anything because when I get close to some of my buddies we turn the boxes off even passing eachother on the highways things start geting crunchie and scare me. main Question here is how do you prevent "BIG RADIO DAMAGE" Thanks Wrong Way

usually you are 20 ft - 30 ft apart. you won't experience damage as long as you both get off the key at the same time. It is just a risk u run. I know a guy who blew all his boxes, 2,4,6,8 at the line...that's a lot of money, but you gotta pay the cost to be the boss. A lot of these big heavy hitters are bringing 3 and 4 boxes with them to the breaks for backups...in ALL classes...

So what I gather from this is:

So long as you have someone signaling when to keydown and then signaling when to let off the key, the radios rx will not pickup all that rf correct? This in turn keeps from destroying eachother's setups....at least most of the time I would hope! My local shop told me never to key even a 2pill box sitting next to my friend...said it would "blow" his radio up. Dunno what would get blown up but apparently it sounds bad.

To me this whole "keydown" comp stuff is a big mystery.

[Capndave]

I want to get the RFX75 mod done to my LTD 29,Ive never had a modified rig beforeso I dont know what expect when I get it back,What else could be done to make it better?

[the_junkie]

I want to get the RFX75 mod done to my LTD 29,Ive never had a modified rig beforeso I dont know what expect when I get it back,What else could be done to make it better?

most keydown guys will probably agree with me on this. if you are looking to keydown, the high powered radios are not favorable. a simple peak/tune and a variable deadkey are all you need.

the more watts your radio is doing, the more splatter and harmonics. if you drive your amps so that most of the watts are on frequency, then you will be better off as you will be sending more of your watts to the gate station...

[Capndave]

This particular radio wont be running an amp,I have a galaxy for that this purpose.So you are saying i should just do a peak and tune?,what should I expect from this?.You see,I live in the Hudson valley,and where I am is CB hell,This will get me out there in skip land?

[the_junkie]

This particular radio wont be running an amp,I have a galaxy for that this purpose.So you are saying i should just do a peak and tune?,what should I expect from this?.You see,I live in the Hudson valley,and where I am is CB hell,This will get me out there in skip land?

if you aren't running an amp, then the rfx may be just fine. beings this thread is about competition setups, i am answering in competition setups.

if you aren't competing, and wish to set up a skip truck, the plan you have will probably get your name called...

[KW KID]

I wish these shoot out people would become a little more sophisticated though. It's time to start doing videogates for the shootouts and put them on youtube! I'd love to see the S meter differences between the classes.

[KW KID]

How to Keydowns work? The multiple antennas set in a line front to back are for "aiming" your signal in one specific direction? I'm not too proud to ask. I really am confused as to what it is exactly determines a winner of a keydown one truck vs the other. Is field strength meter used to determine winner? Someone please fill me in. I've been watching some SICK videos of big gnarly suburbans w/ huge antennas, tons of alts, and crazy rpms. It just got me thinking and I realized I have NO IDEA how they determine a keydown winner.

[rubicon]

Well video gating big watt mobiles presents a massive problem.
RF and vido tapes are a very bad combo. Rf and hard drives are even worse.
I am on my 4th hard drive at the base station, I am very well grounded, but when the beam is pointed over the top of my station my radio computer for watergating and frequency adjustments cooks the harddrive.
This is all at only 7kw bird watts.

[KW KID]

I meant the receiving side, so no TX to worry about. Video the S meter and audio of the receiving radio station radio.