Doubt about Asus WL-ANT-157 Antenna

[dlandiss]

I am interested in your statement that an extender halves the data speed. Is this for all extenders?

I cannot say from experience. The way it was explained to me, the radio in an access point works in only one direction at a time; so it has to receive a packet from the main router, switch to transmit to pass it on to the remote client, then switch to receive for the response from the remote client, and back to transmit again to pass the response on to the main router.

An exception might be that the router-to-extender link (let's say) could be on 5GHz and the extender-to-client on 2.4 GHz, thus using separate radios and enjoying the full throughput of each.

I am still a tad tempted to get three of the 9dBi antennas from eBay. Damn Her Majesty's Customs and Excise.

Buy ten for £25.53 and sell the remaining seven locally to recover the shipping costs<G>!

--Dan in St. Louis

 

[RogerSC]

Hi Dan,

You are right. *Every* environment is difference and it is impossible to guarantee anything. I am interested in your statement that an extender halves the data speed. Is this for all extenders? I'm not too congested here at all on 2.4. Not using 5 yet as only a few items use it.

I am still a tad tempted to get three of the 9dBi antennas from eBay. Damn Her Majesty's Customs and Excise.

Thanks for your information so far.

DrTeeth

Yes, a repeater or extender will halve the speed...it has only one receiver and transmitter, so it needs to listen then retransmit. It can't be doing those at the same time. If you could find an extender with two receivers (not seen one myself *smile*, but I'm not looking for one as I said), that would seem to solve the basic extender/repeater problem of decreasing the wireless speed so much.

 

[DrTeeth]

Yes, a repeater or extender will halve the speed...it has only one receiver and transmitter, so it needs to listen then retransmit. It can't be doing those at the same time. If you could find an extender with two receivers (not seen one myself *smile*, but I'm not looking for one as I said), that would seem to solve the basic extender/repeater problem of decreasing the wireless speed so much.

Transmitting and receiving at the same time is not impossible. That is how all amateur radio repeaters work - they also have one transmitter and one receiver too*, though they do use slightly different input/output frequencies.

*Unless you meant one transceiver.

 

[DrTeeth]

Buy ten[/URL] for £25.53 and sell the remaining seven locally to recover the shipping costs<G>!

--Dan in St. Louis

I like your style .

 

[dlandiss]

Transmitting and receiving at the same time is not impossible. That is how all amateur radio repeaters work - they also have one transmitter and one receiver too*, though they do use slightly different input/output frequencies.

Since the ham radio frequency separation in a typical repeater is less than 1% of the carrier frequency, massive traps are required to avoid receiver desensitization. The ones I am familiar with were physically resonant cavities perhaps a half meter tall and a quarter meter in diameter.

The cost of those and their relative size (even though the wavelengths are much shorter), prohibit WiFi radio from adopting the same technique. With typical transmitters being in the 80mW range no receiver desensitization can be afforded. So, WiFi is probably half-duplex.

Unless ......... 2.4GHz and 5GHz used simultaneously.

--Dan in St. Louis, WØNDA, ex-K9RWK, ex-WØQEV

 

[TonyH]

Hi,
You are talking about diplexer. On VHF repeater the TX and RX frequency is 600KHz apart.
Tony, VE6CGX (HAM since 1960, ex-HM1AY)

 

[dlandiss]

Hi,
You are talking about diplexer. On VHF repeater the TX and RX frequency is 600KHz apart.
Tony, VE6CGX (HAM since 1960, ex-HM1AY)

Exactly, and more definitive. A diplexer is a specialized filter.

A 600KHz spacing at 147MHz is only 0.4%, thus requiring a high-Q filter. That is why large, low-loss cavities are used. Without them, the receiver would be desensitized (or more likely, at amateur radio transmit powers) destroyed.

We have drifted pretty far off the "small net builder" topic, but it has been fun and points out that what is learned in one engineering specialty usually shows up again in another.

--Dan in St. Louis

 

[doubled1979]

I am using 3x on my rt68-u

http://www.ebay.com/itm/2-x-9dBi-RP...59445?pt=US_Cabling_Tools&hash=item20d6ef48d5

noticeable improvement on both bands with these

Did you order style 1 or 2 ?

 

[DrTeeth]

Did you order style 1 or 2 ?

Seller says style 1 is better quality FWIW.

73s de G4DWV/4X1LT

 

[DrTeeth]

@Dan and Tony

Tnx for the info. Now I know how those suckers work.

73s de G4DWV/4X1LT

 

[doubled1979]

Seller says style 1 is better quality FWIW.

73s de G4DWV/4X1LT

Thanks i will order style 1

 

[DrTeeth]

I wonder if "Super Power Supply" is also available on eBay-UK? They have a decent reputation, and may have already worked out the customs tax.

They have 2dB (4.5"), 6dB (7.5"), 7dB (11") and 9dB (15") models.

--Dan in St. Louis

Just a quickie question. In your experience, do the 15" models have a slack joint in that if placed at an angle, they say in place? A few nay-sayers on Amazon were complaining of this.

Thanks

DrT G4DWV/4X1LT

 

[connorm]

i wonder what would happen if you tried using one of these and plugging in 2 antennas to each point for a total of 6 lol

http://www.ebay.com/itm/1-x-SMA-Mal...Coaxial_Cables_Connectors&hash=item1e7fd16cf7

 

[DrTeeth]

i wonder what would happen if you tried using one of these and plugging in 2 antennas to each point for a total of 6 lol

http://www.ebay.com/itm/1-x-SMA-Mal...Coaxial_Cables_Connectors&hash=item1e7fd16cf7

You'd probably start to cook your 'nads .

 

[dlandiss]

i wonder what would happen if you tried using one of these and plugging in 2 antennas to each point for a total of 6 lol

Try this.

--Dan in St. Louis

 

[stevech]

Beware your expectations:

Going from a 2 or 3dBi gain antenna to a 6 or 9dBi antenna (i.e., 3-4 more dB gain), is small compared to the typical path loss for indoor WiFi. That's often 70dB or more. So 4dBi improvement is a small percentage of the 70dB.

If the from-client-to-router signal is, say, 20dB weaker than you'd like (stronger signal = faster data rate and more fade margin), 3-4 dB won't make much improvement.
I suggest using a router whose firmware will display the active WiFi client list and the RSSI for each (router's received signal strength). A few do.