Topband: Connecting Rx antenna to FTDX101

[Mike Waters]

Good answer, Lloyd.

One thing I did is put a small incandescent pilot lamp in series with my
Beverages and my IC-765 transceiver's RX antenna input. The lamp functions
as a current limiter and a fuse. After the lamp, there are back-to-back
diodes to ground, which limit the maximum voltage in either polarity.

I learned this from W8JI. I used a 6.3 volt #47 lamp, but what Tom used
drew less current at its rated voltage than my #47. He could even see it
glow faintly from all the RF that his wideband Beverages were picking up.

That lamp has never blown, but it gives me peace of mind knowing that it is
helping to protect the front end from excessive RF or voltage pulses.

73, Mike
W0BTU

On Fri, Jan 17, 2020, 9:49 AM Lloyd - N9LB <lloydberg at tds.net> wrote:

> That is too much RF power for a receiver input.
> "Front End Protectors" are available for this exact problem:
>
> Array Solutions:
> https://www.arraysolutions.com/as-rxfep
>
> DX Engineering:
> https://www.dxengineering.com/parts/dxe-rg5000hd
>
> Miroslaw Paczocha wrote:
>
> I intend to connect a K9AY antenna to socket 3 of an FTDX101D, this socket
> being menu configured as Rx input. The problem is I measured about 1,5 V on
> the K9AY coax loaded with 50 ohms with 100W forwarded to the Tx antenna ...
>