Partial coverage

[bdt]

koffiejunkie, I've seen connects (mainly by cheating and using a gevreklik antenna (as required)) in places where there should be NONE (just finished one in Morningside Manor yesterday, in fact) and stupidly low/no signal where reason (and GPS) suggests there should be. It's all somewhat of a crapshoot, sadly. So to get a *definitive* answer, IMO The Way(tm) is to have a test done by someone who's properly equipped and knowledgable.

On that note: have (1:GPS (loaded with tower locations), 2: 16dBi yagi & 21dBi dish for testing purposes, 3: ladder, 4: time, inclination and experience to do it right), will travel... (with apologies to Robert A Heinlein)

Oh yea- I'm also just down the road from your Conrad drive location (in Bordeaux)- it's something like a 2km drive.

 

[keithr]

bdt, you're right about having to be properly equipped! I have seen some homemade cockups where guys loose more signal by crappy coax connections than the gain from the antennas they are trying to install.

As you have probably read I run one of those "gevreklik" antennas you talk about but I have an extremely stable and reliable system running here.

It definitely pays to call a pro in if one is not experienced at this sort of work.

 

[Brolloks]

Well there ya have it...

MyWireless 128, Tower: 82, Signal: 13%, SNL: 6, ber: 42%, node: 3

 

[bdt]

keithr.. ah yes, our master and overlord- the coaxial dreaded black snake! Being a ham I guess you would know from this.. A question- the dish you put up to feed off the back lobe of Hurlyvale (I'm familiar with that particular beast- I wasn't able to get a lock to the back of that tower from further away than you are now..)- what size is it?

Also, seeing as you have said dish 10m up I figure you to have at least a 14m cable run (LMR400, yes?)- how much are you running there? I ask as I have know of a site that's going to have a 20m run- ground floor to the top of a 4 storey building. I'm SO glad I'm not doing that particular install!

Back to antennas- you should see the results the 90cm dish gives! I saw one pull up a 14%sig/42%ber to 22%sig/71%ber at the other end of Edenvale, over the hills and FAR away (~4.5km) to the same tower you use- but at least on the north firing node.. But my signal champ is the 24dBi grid- it's achieving 36%sig/71%ber at 5.65km (also my distance record) to Helderkruin.

 

[keithr]

bdt- +- 15m of cable - my UPS (2KW) and smoothwall gateway live below my tower, from where I drive my LAN via a 100mb 4 port switch.

Instead of the 20m run it maybe better to install an old P1 with 128mB to run as a gateway as close to the antenna as possible and run UTP cable instead of coax. This option of course depends on the location but imho the stronger the signal into the mw modem, them better the reliabilty - ie: I do not experience loss of connection as so many users complain about.

My only disconnects happen when Sentech drop me or I check to see if smoothwall is handling dhcp leasing correctly (of which I am still not convinced!)

 

[nonroker]

My signal recently dropped to 10%. I have no disconnection problems. The modem sits in a closet with no antenna.
Anyways, the shorter your RF cable, the less your signal loss, so yeah, getting the modem as close to the gateway as possible is best. And with the modem's ethernet cable you can run UTP all the way to the gateway box.

--
256k ... BAH..more like 25.6k
FSCK YOU Sentech!! [!]

 

[bdt]

keithr: we don't so much have a choice with that 20m run- the office is at ground level and the ONLY way to see the Randburg tower is at the top of their building (Kent Rd valley- WAY low down), over the tops of all those other pesky buildings some numskulls went and put in the way! It's a multistorey office building- would *you* put a delightfully expensive modem/paperweight (depending on current usefulness) in a plastic box up there with no way to know that it's going to STAY up there??

Aside from that- I'm all for doing the long run with CAT5- that's what it's there for. Oh re dhcp leases in smoothwall- why not pull the lease time WAY down, like of the order of minutes and seeing if it drops/reassigns?

 

[koffiejunkie]

Brolloks and keithr, thanks for your input. I will definitely call on your expertise (if that's OK with you) on antenna/dish setups.

Brolloks, I'll be about four blocks up from you - c/o Gordon and Caithness. Hopefully only temporary, though, the place is a bit small, but it's 5 minutes from work in peak hour traffic so I'm not complaining.

Thanks

--
koffiejunkie

 

[koffiejunkie]

bdt, I would definitely put an old P1 up as a gateway up there with the modem and run CAT5 down. I'm sure there could be ways to secure it, no? Maybe a small safe bolted onto a wall somewhere. The only issue would be where you get power from for the box.

--
koffiejunkie

 

[keithr]

bdt, regarding the dhcp lease times - thanks for the idea for testing - Maybe we should start a new thread on that subject!

koffiejunkie, there are many secure boxes/safes available that could be externally mounted - maybe mount the modem at the antenna and run a long cat5 pppoe cable and an extended dc power cable from there to the gateway 20 meters down

 

[koffiejunkie]

Oh, yes, of course, I forgot about pppoe (how could I - that's the only way I would use it!).

What do you suspect Smoothwall of doing wrong regarding dhcp leased times? I use IP-COP 1.4b9 (which I believe forked from Smoothwall long ago), works real nice.

--
koffiejunkie

 

[bdt]

Heh, y'all aren't thinking this through...

1st: the PHB (Dilbert ref.) probably wouldn't be too keen to a) have that expensive toy out there in the "open", for all that it may well be in a fancy, reasonably secured case; and b) this kind of thing adds up PDQ- another thing a PHB is likely to be less than keen on paying for.

2nd: so the PHB/senior tech/SOMEONE from the office wants to take it home (say, for work reasons) for a weekend (how about a long weekend like now)- with NO way to get to the roof short of hiring a ladder, this is going to be inconvenient to say the least!

3rd: every now and then when something goes wrong a modem reset is requied- refer to above. So no, this is quite definitely that special case that needs the long cable run. Now let's all listen to the fat lady sing.

 

[bdt]

<blockquote id="quote"><font size="1" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote"><i>Originally posted by Brolloks</i>
<br />Taken at the corner of Gordon & Judy. These towers are within range, but you'll need to check that. Better still get somebody with a laptop, modem etc to come and check if you've got reception.

Jhb Randburg (Metro Centre) [82] (28.00.19 26.05.40) 1.532km 154° 24% -82dBm
Jhb Hyde Park [66] (28.01.59 26.07.31) 2.938km 314° 18% -88dBm
Jhb Council Mineral Tech [12] (27.58.42 26.05.15) 3.981km 122° 16% -90dBm
Jhb Rosebank [12] (28.2.31 26.8.51) 5.417km 326° 13% -93dBm


MyWireless 128, Tower: 82, Signal: 13%, SNL: 6, ber: 42%, node: 3
<hr height="1" noshade id="quote"></blockquote id="quote"></font id="quote">

Ok, nitty gritty time! I've lived in this area since Feb 1995 and been doing MyWi antenna stuff almost daily since the start of July this year- and I mean I'm out there on buildings with GPS and laptop and antennas (12dBi yagi & 21dBi dish).

Randburg Metro- great distance figure, from my knowledge of the topography I reckon is likely to give best signal. Hey- I connect to this tower from Bordeaux, roughly 30deg anticlockwise from the above location and my usual signal is 42%sig, 18%snl, 71%ber, -63dBm rscp, -81dBm iscp. If I get numbers lower than that (like 30%sig) I reboot the modem to get a better lock! Sometimes being spoiled isn't SO bad..

Hyde Park- for me, tends to lose out to Randburg Metro even though I can SEE the centre from my lounge windows! Actually, with my 8x32 binocular I can make out the MyWi antennas.. And yet this tower gets hopelessly swamped by Randburg Metro- go figure. But it may work out differently at the above location because the intervening topography- it's far enough over from where I am to possibly get different results.

As for Mintek and Rosebank, forget it- they don't exist. Mintek is over the hills (2nd hill away with Ferndale valley in the middle) and FAR away and Randburg Metro is like a searchlight anyway. Rosebank has less of a topographic penalty (but still does) but is WELL hidden behind lotsa buildings. Hell, I know of a site that's *800m* from Rosebank but can't get a lock because of the infrastructure there.

*shrug*- this is my non-tested thumbsuck opinion of what I reckon a test would show. Take it as you please.

 

[Brolloks]

bdt
As I said before: The best is to get a modem, antenna and laptop and test for signal. Whatever the Zone Locator tells you, it's not Gospel, otherwise I wouldn't be getting any connection from where I am.

MyWireless 128, Tower: 82, Signal: 13%, SNL: 6, ber: 42%, node: 3

 

[keithr]

Brollocks is right bdt, especially if you are going to use a high gain (narrow beamwidth) antenna - the laptop helps to align yor signal to the tower

 

[bdt]

Bolloks (and associated mindless fans)- you know, I had a great long weekend and reading your "input" as replies to mine was most entertaining! Thank you kindly for that little bit extra. However, the point of a forum like this is discourse- and that can only happen if both sides take heed (ie- read) what the other has to say. Perhaps you should consider taking up the habit, it's been shown to help in moving the conversation forward and generally resolving things.

 

[Brolloks]

bdt: Before you you have too much fun thinking about your next reply. Learn to read my name and then try to type it the same way.

MyWireless 128, Tower: 82, Signal: 13%, SNL: 6, ber: 42%, node: 3

 

[Robone]

Actually "Bolloks", bdt does exactly what you are all talking about. i.e using a laptop. So you are all talking the same language.

So maybe bolloks was a slip, although, knowing bdt he meant it

 

[Brolloks]

Robone
What's the problem with using a laptop?

I'm quite sure bdt meant it. Point is I see no reason, as seems to happen a lot here, why there should be name calling. Unless my theory is accurate that there is a bunch of immature, regardless of age, people on the forum who feel they have no handle on the English language and therefore cannot express themselves better.

MyWireless 128, Tower: 82, Signal: 13%, SNL: 6, ber: 42%, node: 3

 

[bdt]

You know Brollocks, you REALLY should take the time to read! For instance, if you bothered to actually READ my input to this thread you may even see that I've had a lot of (I believe) pertinent info to add. I specifically refer to my post of [09/24/2004 : 14:37:35].

My previous post was indeed a crack at getting past what seems like an insufferably overblown ego and/or thick skin. Moreover, Robone's input thereafter seems to have been too much for you too! You've shown that you can at the very least recognise your handle incorrectly spelt- well done. Now let's see you actually read some technical content and maybe even come back with something useful. I say again- I contribute (as, I suspect, do most people) to the forum to expand the pool of knowledge out there.

So let's give that a crack, yes?