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Author Topic: Not my weekend!  (Read 21573 times)

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Cumulus

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Re: Not my weekend!
« Reply #15 on: September 14, 2008, 12:07:36 PM »
Hi DC,

My Kuhne preamp has been operating continuously since 24/10/2005 and survived many local thunderstorms. I additionally use a SSE 1090SJ mk2 antenna which is DC grounded. A recent inspection showed the preamp to be in an "as new" condition. Contact Jana Munzert at Kuhne for details.

http://www.polarorbiter.co.uk/Graphics/Kuhne.gif

Cheers






Deadcalm

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Re: Not my weekend!
« Reply #16 on: September 14, 2008, 12:23:42 PM »
Great stuff - thanks, Cumulus.  I've written to Kuhne with a view to ordering.

DC
Go around, I say again go around...

flightchecker

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Re: Not my weekend!
« Reply #17 on: September 14, 2008, 12:58:53 PM »
Quote
"Cumulus" do you read ???:

appreciate you did Cumulus !!!

Karl

Deadcalm

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Re: Not my weekend!
« Reply #18 on: September 14, 2008, 02:42:27 PM »
Cumulus, I se that the SSE 1090SJ mk2 antenna has only 2 dB gain, but the Wimo allegedly has 5 dB.  Has anyone ever compared the two like for like in terms of performance?

DC
Go around, I say again go around...

WiMo

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Re: Not my weekend!
« Reply #19 on: September 15, 2008, 07:00:45 AM »
No guarantee, then, Paul?

I'll see what Wimo say, if they reply.  I think I'll also drop an E Mail to Elad, the manufacturers and see what they say.

DC

Hi,
to which address did you send a mail to WiMo and when? I have not received anything over the weekend.

Rgds,
Ekki/WiMo

Deadcalm

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Re: Not my weekend!
« Reply #20 on: September 15, 2008, 07:20:06 AM »
Hello EKKi at Wimo, thanks for your input.

I sent the following E mail to Support@Wimo on 13th September, at 15:58:

______________________________________________

"Hello
 
I purchased a Wimo antenna, cable, Bias Tee and Preamp for my Airnav RadarBox.
(14th February, Wimo Order 080214040)
 
One or other of the components seems now not to be operating correctly.

Until now, the range of acquisition of targets for my RadarBox has been around 250 nm, and I've been very pleased.
 
Suddenly, the range has dropped to less than 100 nm.  I have checked all the connections (which were all sealed with self-amalgamating tape) and all seem dry and clean.  I have tried the RadarBox with the magnetic antenna supplied by Airnav, and that works OK - better than the current results with the Wimo.  Is it likely that one of the Wimo components has failed?
 
Can you advise the best course of action, please?  Are these units under guarantee?
 
Regards
 
(My Name)"

__________________________________________

Hope no-one minds me adding the text here.

Regards

DC
« Last Edit: September 15, 2008, 07:22:28 AM by Deadcalm »
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Deadcalm

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Re: Not my weekend!
« Reply #21 on: September 15, 2008, 02:22:16 PM »
Did you get that, Wimo?  No reply from you here or by E Mail as yet...
But I have had a reply from Kuhne.

DC
Go around, I say again go around...

WiMo

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Re: Not my weekend!
« Reply #22 on: September 16, 2008, 06:26:39 AM »
Yes, got it now (I only check this forum once a day, if at all). I will reply by mail.

Rgds,
Ekki/WiMo

flightchecker

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Re: Not my weekend!
« Reply #23 on: September 16, 2008, 04:06:33 PM »
Quote
Cumulus, I se that the SSE 1090SJ mk2 antenna has only 2 dB gain, but the Wimo allegedly has 5 dB.  Has anyone ever compared the two like for like in terms of performance?

Deadcalm, don’t care too much about 2 or 3 db of “antenna gain”. There is al lot of “believing” in those figures. The “dbs” are refernced to what is called an isotropic (punctiform / ball like / ideal) radiator, uniformly radiating its transmission energy  into ALL directions, whilst “real” antennas all develop different kinds of directional behavior, thus “concentrating” their energy into this direction(s). The above applies for transmitting antennas,  but vice versa for receiving antennas as well. 
And, by the way: as you are going to use a preampp, this one really will give you a lot of “dbs” by its amplification, even if some of them are “eaten up” again by your 18 meters of coaxial cable. (~ 3 db @ 20 meters of ECOFFLEX 10)

Cumulus of course is doing great by operating a “DC grounded antenna” as you might have read. Such antennas using a small inductive element at their “feeding point”. The inductance almost does not have influence on the RF signal travelling to the receiver, (ANRB) but shortens possible Electrostatic Charges to ground, thus preventing the receiver to beeing hit by "ESD".

Kind regards


Karl.
« Last Edit: September 16, 2008, 04:10:52 PM by flightchecker »

Deadcalm

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Re: Not my weekend!
« Reply #24 on: September 16, 2008, 04:20:20 PM »
Thanks for the info, Karl.  Wimo have asked me to send the preamp to them - they'll check it and see if it needs repair.  Don't know if it'll be a warranty job, though.  In the meantime I've ordered a new preamp from Kuhne, so I should be up and running by the end of the week.  And if the Wimo preamp is faulty and can be repaired, I'll have a spare!

So what would I additionally need to have a "DC grounded" antenna?

DC
Go around, I say again go around...

flightchecker

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Re: Not my weekend!
« Reply #25 on: September 17, 2008, 03:03:11 PM »
Quote
So what would I additionally need to have a "DC grounded" antenna?

Hi Deadcalm,
it is the antennas design, that makes it a "DC grounded" antenna. As Cumulus mentions in this thread before:

Quote
My Kuhne preamp has been operating continuously since 24/10/2005 and survived many local thunderstorms. I additionally use a SSE 1090SJ mk2 antenna which is DC grounded. A recent inspection showed the preamp to be in an "as new" condition. Contact Jana Munzert at Kuhne for details.

he uses this type of antenna, (in conjunction with the also mentioned amplifier) obviously without any problems. Looks good.

If you were able to do some mechanical "tinkering" and soldering, (or if you've got a friend to do so, may be even a radioamateur) I could offer you some hints on building a small device to be put between the antenna (end of coax cable) and your receivers input, thus having the same effect as has an antennas "DC grounding".

In case of interest just let me know via e-mail. AirNav does not like the nickname of  of the "black box" above. Believe it or not...........


Regards

Karl

Added:

check this link for a "DC grounded antenna:  http://www.ssejim.co.uk/26-sseads1090sj.htm

and notice:

Quote
To greatly reduce noise caused by atmospheric discharges-lightening, etc., all metal parts are DC - Grounded with the antenna showing a DC - Short Across the "N"Coaxial Socket. This also greatly reduces problems with RF-Pre-amp, Input Stages

K.

« Last Edit: September 17, 2008, 05:59:44 PM by flightchecker »

Deadcalm

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Re: Not my weekend!
« Reply #26 on: September 17, 2008, 07:35:43 PM »
Thanks for the info, Karl.  I have looked at the SSE Jim antenna already, and I'm considering it.  I didn't really want to have to buy another antenna, but if I end up with a spare preamp, a second aerial could be useful for an alternative location.

DC
Go around, I say again go around...

CoastGuardJon

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Re: Not my weekend!
« Reply #27 on: September 17, 2008, 08:55:25 PM »
Hi all, not got an RB yet, but have negotiated one a Christmas pressie from my better half, who can't see why on earth I want to get one!   I do a lot of SW Listening on various receivers.    With all electrical connections out of doors, I lag connectors (and try to get some inside co-ax, after soldering) with electricians' silicone grease, which is available for around £3.50 per 50g tube, water and damp hate it - I've never had any problems with corrosion.    Water can get into co-ax and will actually move through it by gravity and capillary action.   In preference to self-amalgamating rubber tape, which will deteriorate, perish and crack, I try to use cable gland covers which can have silicone grease put in before fastening with wire tie at the wide end, you just cut off the blind end to get a slightly small diameter than the outer of the co-ax you're using.    It used to be possible to buy purpose made lightning arresters with double-ended SO239 fitting, which had a very small spark gap (about 0.001 inch) from the internal conductor the outer body which had a heavy cable to earth - electricity, being extremely lazy like me, will take the shortest and easiest route to earth.   Even with these fitted, it is good practice to disconnect outside antennas from the back of the boxes, and ideally earthed.

Thanks to all those who posted replies and PMs to me, when I inquired SBS-1 or AirNav RadarBox on the Kinetic site, before the post was locked.   This protectionist attitude has swayed me from the SBS-1 route (which I had more or less decided to go with) and the helpful attitude and advice from RB users (some of whom have feet in both camps) and watching what goes on in this Forum.    Hopefully, I'll be able to make some useful input in here.
« Last Edit: September 17, 2008, 08:56:56 PM by CoastGuardJon »
ANRB :  AOR AR8000 : Icom R-7000 : Icom IC-R9000 : JRC NRD-545 : OptoElectronics Digital Scout and OptoLinx Interface; Realistic Pro-2005 : UBC 800XLT - listed in alphabetical order, not cost, preference, performance or entertainment value!

AirNav Support

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Re: Not my weekend!
« Reply #28 on: September 17, 2008, 08:59:12 PM »
Welcome CoastGuardJon.

You won't get your post locked here if you compare products, why? because we know RB comes out top :)
Contact Customer/Technical support via:
http://www.airnavsystems.com/contact.html
[email protected]

CoastGuardJon

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Re: Not my weekend!
« Reply #29 on: September 17, 2008, 09:09:17 PM »
Welcome CoastGuardJon.

You won't get your post locked here if you compare products, why? because we know RB comes out top :)

Thanks for the welcome.    I was pointed to your detailed camparison document by another Forum member, and while I don't swallow it 100% - it is a very good sales pitch though! - at least you're open minded, and I have seen criticisms in here which then been taken on board and addressed.    I don't expect total perfection and satisfaction from any supplier (not just in this sort of equipment, but right across the board), but at least you allow resonably free discussion, for which I thank you - having done the brown-nosing, I don't suppose you have the odd spare unit around, I could borrow and review..............?
ANRB :  AOR AR8000 : Icom R-7000 : Icom IC-R9000 : JRC NRD-545 : OptoElectronics Digital Scout and OptoLinx Interface; Realistic Pro-2005 : UBC 800XLT - listed in alphabetical order, not cost, preference, performance or entertainment value!