On Tue, 22 Dec 2009 10:32:51 -0800 (PST), Hisashi T Fujinaka wrote: >Motorola Powervoice speakers should have some shielding because they >were meant to work with Motorola mobile radios. Yes, but Motorola radios are VHF/UHF. In general, things that kill RFI at VHF/UHF may not fix it at HF (like "pin 1 problems") and vice versa. 73, Jim K9YC