AirNav Systems Forum
AirNav RadarBox and RadarBox24.com => AirNav RadarBox and RadarBox24.com Discussion => Topic started by: owensy on September 29, 2009, 07:10:37 PM
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Hi,
Just got my box today and I got a free antenna, can anyone point me in the right direction for co-ax cable and connectors?
The antenna is a Radar-Rama.
Thanks,
Paul
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Hi Paul,
I started off with a Radar-Rarma fitted outside,it did`nt last more than approx 6 months,rusting & reception dropping off due to the deteriation of its condition.I mentioned this to the owner of a local ham radio store who said he thought it was an indoor aerial,although I dont think it states that in the instructions.Ref the coax always go for the thicker top end stuff,preferably Westflex 103,or RG213.Use N type connectors rather than PL259`s if poss,the N type are far better matched to the 1090mhz frquency.It also depends on how long your cable run will be,if the aerial is going in the loft with a short cable run you might get away with a thinner & much cheaper 50 0hm coax.
My set up now is a DPD 1090 antenna,60 ft high, N connector onto the aerial,20mtrs of westflex 103 to another N connector with an N to BNC adaptor then straight onto a JIM preamp then onto the radar box with an SMA to BNC adaptor.
Hope this gives you some ideas,no doubt some other forum members will also give you some useful advice.
Regards Paul,voyager8.
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Many thanks!! I was thinking of mounting it the loft, next to my scanner antenna. I guess I need an adaptor to fit in to the back of the box itself?
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Hi Paul
Yes you will need an SMA adaptor to fit the back of the box.You can get an SMA male to N type female adaptor for £2.49 from truck-kingradio on ebay.This allows you to then join straight onto the N connector fitted on the thicker Westflex/RG213 coax. Be careful not to put too much strain onto the SMA connector on the back of the radar box as the westflex/RG213 is stiff/heavy to handle if you go for this option.
Maplins do an SMA male to BNC socket adaptor part no RS85G for £2.39 more suitable for a patch lead or the thinner coax options.
If you go for the N connectors onto the Westflex coax you will need the special UHF 242 N connector which has a larger diameter centre pin to go straight onto the thick dialectric in the centre of the coax.I got mine from Nevada Radio in Portsmouth,2 connectors for £9.99 inc free postage !!.
You can also find instructions on how to assemble the N connectors at the following link:-
www.gandalf.nl/pdf/How%20to%20assemble%20a%20N.pdf .
Hope you will find all of the above some help for you.
Regards Paul,voyager8.
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Hi,
Just got my box today and I got a free antenna, can anyone point me in the right direction for co-ax cable and connectors?
The antenna is a Radar-Rama.
Thanks,
Paul
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Hi Paul, i am a a new member as well. However, being a radio ham i`ve already got a tower etc so can get stuff up quickly. Didn`t have any suitable coax floating about so i cheated and used satellite (RG6) as a spare until i can get the real thing. I have a 50 foot run of the stuff and it appears to be doing very well. I also cheated and spliced the cable into the supplied curly whirly antenna supplied with the box. Certainly works OK and so far from this location using the antenna rather than the web i`ve logged an average of 80 contacts in four hours (0715 1245) Qth here is Pontefract West Yorks. Incidentally, the satellite coax is 75 Ohm but as we are just using the stuff for receive purposes it does the job. Bi now, Roger
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Be leary of those N to SMA adaptors. Some of the cheaper ones will sometimes make an intermittent contact, or introduce signal loss. If you can, get a short length (1-2 feet) of small diameter cable, and install a female N at one end and a male SMA on the other. Much more secure setup that way. I found a 2 foot length of cable with male SMA's on both ends at a hamfest. Cut it in half, found a good quality female N with the correct cable diameter end piece, and soldered it on. Works like a champ.
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I've just received a 1090SJ MkII from SSE, which appears to be an extremely well designed and manufactured product (ordered Saturday, delivered Wed. - pay by those old paper things called cheques! Jim doesn't do cards - it would push the prices up) which has an N female connector. From the info. that comes with it, it is a half wave dipole design in a GRP tube, it is DC grounded - so there should be no static problems. For the RB, Jim supplies a superb patch lead about 18" long, with N female socket at one end, and a right angle SMA plug at the other - cost £5 if supplied with the antenna, again, this is a very high quality product and is infinitely preferable to an adapter, as it takes all the strain off the RB SMA socket. Henry Westlake makes up and supplies high-quality patch leads (and, I suspect, makes those supplied by SSE).
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I've just ordered both the 1090SJ MkII from SSE, and the patch lead, and also a 5 metre Westlake 103 cable. As i'm in Australia it may take a week or two to get them, but just had a quick question.. and I realize it will be a gamble but thought i'd try anyway.
Where I live most of my signal seems to come from reflections off all the office buildings that surround my apartment. I have very little view of the sky, and i'm on the opposite side of the building of the flight paths etc. My apartment however faces an office building which does face a flight path and I believe most of my signal is bouncing off the buildings etc.
Do you think the antenna will improve things a bit, or none at all compared to the stock antenna that came with the RB? I tend to get aircraft timing out all the time, then re-appearing, then timing out etc.. and the distance is not that great. Higher altitude aircraft tend to be a lot better than lower altitude aircraft. My polar diagram also tends to show I pick up more aircraft 20 Kilometers south of my location and less of the aircraft only a couple of Kilometers near my location under the flight path.
I'm hoping it's not worse, but I figured it's worth a try either way. What do others think? Did I just waste my money?
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Hi Gleff, I apologise if it sounds as though I'm trying to teach Granny to suck eggs, but be aware that Westlake 103 has a single conductor in the middle, I've just ordered a roll from Nevada, then realised this, and am now trying to get the order amended to RG213 with a 7 strand centre conductor. We are subject to a lot of high wind at my home location, and I want the more flexible cable to get around the many near right angle corners!
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Hi Gleff, I apologise if it sounds as though I'm trying to teach Granny to suck eggs, but be aware that Westlake 103 has a single conductor in the middle, I've just ordered a roll from Nevada, then realised this, and am now trying to get the order amended to RG213 with a 7 strand centre conductor. We are subject to a lot of high wind at my home location, and I want the more flexible cable to get around the many near right angle corners!
Thanks.. I wasn't aware but then again, it's just going to be draped on the ground in a straight line anyway so it should be flexible enough for my use. The big question though is do you think the antenna, and cable will improve my signal situation if the majority of my signal appears to be reflections?
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Gleff,
It certainly will not be any worse so it is worth a try.
Any reflections you get will be weak hence the signal timing out.
The basic rules are to get an outside antenna, as much in the clear as possible, and as high as possible. Any indoor antenna will have massive signal loss due to walls etc.
Good luck.
J.
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Thanks.. I wasn't aware but then again, it's just going to be draped on the ground in a straight line anyway so it should be flexible enough for my use. The big question though is do you think the antenna, and cable will improve my signal situation if the majority of my signal appears to be reflections?
Hi Gleff, if the 103 is installed as "hard" permanent wiring, no problem, but if it's likely to be subjected to repeated bending or disturbance, I'd prefer the RG213, these are heavy cables and need support to take the load off the antenna connector.
The higher and clearer you can get any antenna, the better, but over a certain length of downlead, you will suffer from diminishing returns, the cable loss will exceed the signal gain! This is where a 1090 mast-head pre-amp (as close to antenna as possible) can come into its own and give the desired signal a boost.
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Thanks for that.. I'll see how it goes initially.. I can always buy a new cable if it becomes a problem.
Can I buy a 1090 mast-head pre-amp on it's own? If so, what should I get, and where? I've as good as got the antenna, and cable so I won't be needing any kind of kit.
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Hi gleff, this is the sort you need
http://www.airbandonline.co.uk/viradac_a12-1090.htm
but there has been a lot of discussion on here about whether a pre amp is much use, I have one of these on my setup but if I disconnect the preamp power from the bias T I don't lose any aircraft so is it actually doing anything?
Hope that helps
Stuart
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Hi Gleff, see what your reception's like with what you've already ordered. If by siting the antenna 20+ feet higher (roughly the height of a standard scaffold pole), you get drastically improved traffic, but the signal is attenuated by the length of co-ax, then a mast-head 1090 pre-amp could come into its own, by boosting the wanted signal at the antenna and overcoming the losses introduced by the co-ax. Using a pre-amp at the RB end of the feeder is (IMO) a total waste of time, money and effort. Every connector inserted into the feeder introduces its own losses and noise, a pre-amp does the same. There is a pre-amp around JIM M75, but (IMO) this is too wide a band range for 1090, but very good for scanners.
For 1090, use either the Elad as suggested by Stuart above, or the Kuhne 1090
http://www.kuhne-electronic.de/en/shop/143_Vorverstaerker/article:342_KU_LNA_1090_A_TM
Youa can always add these later, wait for your new gear, see how you get on!
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Update: I received the antenna and cable today.. Wow.. what a difference it's made. Not only are aircraft NOT timing out nearly as often as before, but I'm picking up 2-3 times more aircraft, and at a distance of around 190 nautical miles at high altitude, and for the first time, i'm seeing aircraft on the 'ground'.
To say I'm pleased with the antenna is an understatement. It's like comparing night and day. The best part is, the aircraft aren't disappearing after 30 seconds like before.
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Hi Gleff - glad that you're getting this better performance. So most of your reception is coming through reflections - including from the ground?
I hope you're sharing on the network - will check out Sydney later.
Rod