7 dBi Antenna Mod Kit for WNR3500Lv2--what do you think?

Mokona: Sounds great, can you give details? I found just the bare antennas for $12 (maybe each, not sure) without the cables at DigiKey. Mouser was more. Looks like a great mod, thanks for mentioning it Peter!

Those both seem like great choices, so I did a comparison:

Peter's link shows a total cost of $23.49 shipped cross country to CA, with an arrival time of a couple days. The seller also includes instructions and such.

Mokona's option costs $7.70 shipped partly from China and partly from Hong Kong to the USA, may take a month to arrive, has no instructions, and the 20cm cables may be a bit long so may hang further down the case. If you happen to be in Hawaii, ordering from foreign countries may be as fast as from the east coast, but for mainlanders, the time difference is quite a bit more.

Both are very good choices, turnkey or cheap. For $15 extra, it arrives quickly with instructions. I could go either way.

[I may no longer buy anything from Mouser or Digikey, ebay or direct import are much cheaper!]

Mokona,
Thank you for the tip, adding heat sinks is a great idea. I suppose if increasing it's power output through a firmware mod as well, one might want to add a fan, even with thermistor, though the side of the case. Since it has a 12v supply, that should be easy enough to do (soldered internally or wired to the supply).

I might try your route, but being a forum, I was expressing the options for any potential reader (from novice to expert):
1. Import pieces oneself from out of country (adds time for completion)
or
2. Buy from an US east coast supplier (Peter quoted the link) with a 30 day money back guarantee, who ships quickly and gives instructions and such. In fact that seller makes kits for about 40 models, with a 99.5% positive feedback rating. Not bad for those who don't mind paying $15 extra for convenience.

Peter: Excellent idea, without your post I wouldn't have known of this mod.
Mokona: You clearly know what you are doing and how to save money. Wonderful tip adding heat sinks. Do you have suppliers in mind for the heat sinks, and maybe a cheap, quiet large fan, especially with thermistor? Perhaps a more powerful set of compatible antennas?

I did a bit more research, and apparently antennas need not match but give the router "a choice" for less dropout, in fact only one good antenna is needed per an old dd-wrt forum thread. Also, if the router is near all your equipment, throughput could be improved by turning down the broadcast signal to eliminate reflection induced drop-out. Lastly, since I want to reach a far away field in line-of-sight, I should use a directional antenna; few cheap panel antennas exist, but yagis are common and cheap. What about adding one directional antenna, and leaving the other stock or 7dB gain omni?

Alternately, what about using the WRN3500Lv2 stock (even turned down, testing to find the fastest throughput for a particular setup), and putting the broadcast burden on an old, cheap(used), slow router as an access point pointing out the window (or mounted outside) on another channel? That throttles the guest AP signal, because the AP would be a slower device (WRN54G or similar)? This minimizes burden on the WRN3500Lv2, maintains the warranty on the new router, and if it burns out an old router: just get another used for $15.

BTW: For a lot more money, one can buy high-end omni and directional antennas at Fry's now. (not me, I'll import!)

Nice image Mokona,
It clearly describes that high gain omnis have limited coverage, so are only good for one floor of a house.  Yagi output is different; more elements mean more directionality and gain - and cheap models are on eBay for $20-$30.  Panels are extremely directional, and one guy sells cheap home-made units on eBay worth considering, but commercial panels can cost up to $8,000!  I'm still considering a cheap panel, but Yagi coverage looks like this example:

After some research and asking around, I imported the items Mokona referenced near the beginning of this thread, plus a new 14dBi panel antenna, a used Linksys WRT54-GS v1.0 with 8MB Flash, and converters to use all those antennas on either router. When everything arrives I'll use a wifi detector program and test every combination from varied locations and share the results. I'll try adjusting the broadcast output, and compare replacing only one stock antenna as dual internals claim "diversity." Why test the old wRT54GS? To compare the routers and test cascading routers. Both routers allow Tomato and DD-WRT big/mega builds, to compare identical setups. I may not have results for a month, depending on delivery time to CA.

Cost: $3.74 for antennas, $4 for cables, $3.60 for converters RP-SMA to RP-TNC (to WRT54GS), $21.79 for "hurricane proof" outdoor (works indoors) 14dBi panel antenna, $19.50 for WRT54-GSv1.0 on eBay auction; shipping included. WRN3500Lv2 $69+tax bought at Fry's. Total project cost: ~$125.00 for cascading routers & multiple antenna configurations. I can't afford more combinations!