[Elecraft] Rx-In/Out used for exteranl SDR Device

[Joe Subich, W4TV]

This only works 1) if the SDR impedance is consistently high from
100 KHz to 54 MHz and 2) the SDR has excess gain to compensate for
the loading from the K3 receiver.

However without a splitter, there is no protection for the K3 receiver
against spurious signals generated by the SDR!

73,

    ... Joe, W4TV


On 2021-12-05 1:35 PM, Bob McGraw wrote:
> I use a pair of BNC to BNC cables, about 4" long, from the RX OUT and RX 
> IN to a "T" connector.  The 3rd port of the "T" goes to the SDR.  I find 
> that the SDR input impedance, is nowhere close to 50 ohms,  is high 
> enough that it doesn't load the signal on the main RX.   Again, no 
> splitter required.   No loss encountered.
> 
> Yes, one does have to select RX ANT on the front panel for this to be 
> active.
> 
> 73
> 
> Bob, K4TAX
> 
> 
> On 12/5/2021 11:36 AM, elecraft-request at mailman.qth.net wrote:
>> Message: 22
>> Date: Sun, 5 Dec 2021 17:35:46 +0000
>> From: Dave<dave.g4aon at gmail.com>
>> To:elecraft at mailman.qth.net
>> Subject: Re: [Elecraft] Rx-In/Out used for exteranl SDR Device?
>> Message-ID:
>>     <CABiKjG5c=s76xxwaxHJiiQYr+C3RtR_FYRHCb3YsN++=Xnn_=Q at mail.gmail.com>
>> Content-Type: text/plain; charset="UTF-8"
>>
>>> I see about a 3 S-unit drop in signal
>>> level when routing through the splitter
>> Pete (N4ZR), what do you see with a straight cable linking in/out?
>>
>> I have no idea about Minicircuits splitters, but my home made one had a
>> measured 3.1 dB loss at 29.7 MHz.
>>
>> 73 Dave G4AON