[Elecraft] K3S relay noise when using Rx ANT IN port

[Petr, OK1RP/M0SIS]

David,

the problem is that original KD9SV FES unit is not protecting your radio
against the another RF power sources (SO2R or MM site operation)... FES unit
is disconnecting ext. RX antenna and grounding the input RX port just when
the unit is activated by own radio PTT signal.

In that case the limiters like FEP seems to be much better and it will do
the job perfectly.

Martin, OK1RR has new design of the FEP RF diode limiter for homebrew, just
the article is in Czech language:
https://www.okdxf.eu/index.php/technika/272-ochrana-vstupnich-obvodu-prijimace

Do not worry to ask him for help. I am using his design as an upgrade of his
preview KD9SV saver project and it works perfectly as everything designed by
him.

An interesting thing on EA4TX TRX-FEL design is that it can protect also all
the main TRX ports on the radio (not only ext. RX antenna port) in SO2R and
MM operation.

Ref: 
AS-RXFEP Limiter (Array):
https://www.arraysolutions.com/surge-and-rf-protection/as-rxfep
RX-FESSS (KD9SV): https://www.dxengineering.com/parts/svp-sv-fesss
DXE-RG5000HD Limiter (K3LR):
https://www.dxengineering.com/parts/dxe-rg5000hd
TRX-FEL (EA4TX): https://ea4tx.com/en/tienda/frontend-limiter/trx-fel/
RX-FEL FE Saver (FEP EA4TX):
https://ea4tx.com/en/tienda/frontend-limiter/rx-fel/
RFEP (Cross Country) UK:
http://www.crosscountrywireless.net/receiver_protection_unit.htm  
FES KD9SV (OK1RR):
http://www.ok1rr.com/index.php/technical-topics/39-yet-another-front-end-saver
FEP Diode Limiter (OK1RR):
https://www.okdxf.eu/index.php/technika/272-ochrana-vstupnich-obvodu-prijimace



-----
73 - Petr, OK1RP 
"Apple & Elecraft freak"
B:http://ok1rp.blogspot.com
MeWe: https://bit.ly/2HGPoDx
MeWe: https://bit.ly/2FmwvDt
--
Sent from: http://elecraft.365791.n2.nabble.com/