Coily Burban rebuilt.

[mrcoily]

Sounds like a good set-up, did you have time to compare the full 1/4 wave set up and record results to compare to the loaded antennas?
One driven antenna and all reflectors, or is the back grounded?
The reason I ask is Shockwave has been doing modeling with no back door and it looks good, did you get a chance to read that thread?

I have to admit it looks like a real clean install.


73
Jeff

The back antenna is grounded reflector,then hot..then 3-4-5-6 antennas are all isolated from ground from the boom ,,the number 3 antenna does not show alot of gain but when you put the 4 director on the field numbers jumped 10 points on the meter..then the 5th antenna bumps it up a bit more then the number 6 antenna jumps it up another 6 points...so lets say,, and these are actual gain figures i am using now...field strength single antenna+40. with reflector and all 4 directors+ 70...thats on a 1-100 meter so you can figure it out but thats about 30 points forward...but i am not sure as of yet how it will react sitting next to another vehicle as i will get refect in the system..anyhow its all good fun will see.Now on the sticks that i used you can take about 12 points off them figures that what field tests show.As far as computer models there not very accurate as what the computer says and the math calculation show there as good as the paper it is printed on...the field meters are the only way to fly and the more them the better..i wiped mfj out when i order..lol...73sss dinner time.When i have more time ill see if i can get some actual graphs and numbers out here..but its bascily what you see above.Also this a brand new setup and additional tuning will be done and element spacings..so its far from done but my reflect is low..10 watt slug wiggle wiggle.so good for now..

 

[BOOTY MONSTER]

what is the "point" scale you're using ? is a point a db ? a s-unit ? or some other meathod of measuring the RF signal ?

 

[mrcoily]

read it again 1-100 mjf820 meter.

 

[AudioShockwav]

I think he meant MFJ-802.
It is a relative field strength meter.
reads o to 100.

MFJ Enterprises Inc.

73
Jeff

 

[mrcoily]

yep thats the one..0to100 my bad.

 

[BOOTY MONSTER]

thanks ASW . i looked at the owners manual for the 802 .

http://www.mfjenterprises.com/pdffiles/MFJ-802.pdf

it says it has a 1-100 high resolution scale , but i didn't see anything that gives any reference how many points equal a db or vise-versa .
oh well .....

 

[W5LZ]

It's just a reference scale, not related to any particular values per unit. If you want to do the calibrating per each test session/position, you can. But you have to use a known reference signal over a known distance, and that'll be loads of fun! That meter offers no 'filtering' or selectivity at all, so any signal of any frequency near by will add-to your test ot standards for calibrating. That's even more fun!
- 'Doc

 

[mrcoily]

Maybe... but 30 points is 30 points,on a 0-100 meter with lots them you can get a solid look at your forward power..from a starting point of a single hot radiator to your finished product...plenty gain for sure dont really matter but the meter tell you whats up pretty cool...i suppose you could figure out the gain of a 1/4 wave radiator then use a few calculations if a person wanted..but the single hot coil already beating a 1/4 wave radiator so just have to add that loss from the 1/4 wave in..kinda a pain...but if you want use your super forum powers you can figure it...my figures..single coil radiating at 40 on the field meter..and a 1/4 wave 102 or stick radating at..28..on field meter if you know what a 1/4 wave does you got a fair idea i leave it up to you guys to pick at..seeyeah..

 

[BOOTY MONSTER]

have you ever tried dead-keying 1 watt , then 10 watts and then 100 watts with the same antenna to see how the meter reacts to 10 db and 20 db of gain ?

 

[Se7en]

mr. coily you have a pm. also i dig your setup! wish i could see it in person

 

[Robb]

I think he meant MFJ-802.
It is a relative field strength meter.
reads o to 100.

MFJ Enterprises Inc.

73
Jeff

Soooo . . . Just an observation here . . .

The antenna(s) on MrCoily's Maul are all vertically polarized - right right?

But the field strength meter antenna is horizontally polarized. Was it intended for a Ham's dipole antenna? Maybe he needs to get/use one that is vertically polarized - eh?

 

[mrcoily]

The meters are horizon type but that is to give an better stable meter reading ..I could turn them vertical if that would please ...dont make no differance..

 

[wavrider]

MR C is discussing his set-up on the burb.

To hell with the MFJ meter, it is for reference only, sort of like a satellite signal finder. Set the sensitivity and let it fly with whatever signal is coming in.

The fact is that as more elements are added to the burb antenna system the more gain it gets and the reference meter shows more deflection.

Nothing new, the antenna theory handbooks back that up IE more elements more gain, with boom length/spacing figured in.

A good comparison would be nice as mentioned earlier, 1/4wl steel whip with 1w dead key then the coily thing with 1 watt dead key, using one meter as a reference. That will then show which one is putting out more of a signal where the mfj meter is positioned.

The positioning of the reference meter plays a big part of the test, MR. C has mentioned he has many in different locations and distances.

Set up looks great, keep on adjusting and testing it, looking forward to hearing how it does in the shoot outs.

 

[6.0 Liter]

Soooo . . . Just an observation here . . .

The antenna(s) on MrCoily's Maul are all vertically polarized - right right?

But the field strength meter antenna is horizontally polarized. Was it intended for a Ham's dipole antenna? Maybe he needs to get/use one that is vertically polarized - eh?

That meter is sweet Robb..........all you have to do is flip it and PRESTO, you have either vertical or horizontal polarization, the only thing I don't like about mine is, it don't seem that sensitive. I wouldn't even see the needle wiggle with a 1 watt dk 20 ft in front of my truck. Thats with the sesitivity turned all the way up. Mabe I am just a stupid:blink: user......idk.....

 

[BOOTY MONSTER]

is it possible coily is using more than 1 watt ?