replacing the RX filter with a balun on the c139

[Joshua Lackey]

Quoting 246tnt at gmail.com (246tnt at gmail.com):
[...]
> >(As an aside, the baluns that Sylvain chose aren't perfect for the US
> >frequency range, but they should work okay.)
> 
> The hi band one if the one recommended for both PCS and DCS.
> For the low band it's indeed E-GSM but the graphs are virtually flat,  
> insertion loss varies by less than 0.5 dB. Return losses are a bit higher  
> but I doubt that it matters much.

Yes, not "baluns" but "balun".  The HHM1523C1 E-GSM side balun is
slightly better in the 900 band.  It looks like the HHM1523B3 is
exactly the same balun with the same pin-out except slightly favoring
the GSM-850 range.