There is indeed marginal improvement with the secondary antenna as I have tested a year ago. This is probably because the secondary "antenna" circuitry actually spans a good part of the board:
http://www.mylilsite.net/images/sdar430w.jpg
You can see the inverted F antenna has one line connected to the signal source (upper), while the other (lower) is connected to what appears to be the common ground. This would definitely result in the secondary antenna actually being larger than the primary/external, thus better signal. _________________ WRT54GL 1.1 v24 preSP2 r14896 | RNX-GX4 v24 preSP2 r14929 | 2x AR430W v24 (both bricked ATM) | 2x F*n2100 Legend Pre4.5U & v24 preSP2 r13525
I tested it, but if i do the above, the signal strength will be less than 10% compared to the original (diversity disabled, rx antenna primary) setting.
I use the 15/4/09 build.