This is very likely a IM3 issue. Shielding won't help. You need to surpress the IM3 on the 2M output.
I have a torpedo sized cavity filter that knocks down the IM3 by 40 dB and I see no desense.
GL - 73 - Paul - W2HRO
On Fri, Aug 3, 2018, 12:11 Patrick STODDARD (WD9EWK/VA7EWK) < [email protected]> wrote:
The RF shielding isn't over components on the circuit board. The inside of the RSP1A's plastic case has metallic paint which serves as the shielding. From the same review you cited at:
"Like the RSP2 the plastic case is now spray painted with metallic paint on the inside. This works almost as well as a full metal case to shield from unwanted signals entering directly through the PCB, instead of through the antenna. We do still notice some leakage making its way in through the coax shield, but it is relatively minor with the shielding."
I have used my RSP1A to receive satellite downlinks, and have not experienced issues as VA3ASE mentioned. I'm not using an FT-991 or FT-991A, but use a variety of other radios (HTs, IC-2730A, FT-817, TM-D710G) for the uplink side of my station with the RSP1A and a tablet with HDSDR for the downlink.
On Fri, Aug 3, 2018 at 3:50 PM, Zach Metzinger [email protected] wrote:
On 8/3/18 10:07 AM, VA3ASE wrote:
Zach my understanding is that the RSP1A is still shielded despite the
plastic box, but I actually have access to an RSP2pro in a metal case
I can try out as well. I've never heard of a USB EMI filter before, I'll look into that. I'm using a quality TrippLite USB cable with molded
at each end.
Based on the pictures shown in the review located at the following URL, there does not appear to be any shielding over any RF component.
--- Zach N0ZGO
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