[Elecraft] K3 with SDR-IQ and external antenna for SDR-IQ?

[KD7YZ Bob]

Don tapped out:


> To receive VLF you will need a VLF converter.
Well,  that would be neat if Elecraft made one ... would integrate
nicely. Then, since all I want to do is RX, I'd be isolated and not
worry about frying the SDR-IQ.

However, that's not the case, so I have to run an antenna straight into
the SDR-IQ, and I have already done this twice. The first time, I was
handily listening down at 17KHz with just the antenna to the SDR-IQ.

Second time I was also xmit on the K3 and tuning the 450 ladder line.
The SDR took a hit, I fear.

Thus, I want to switch the SDR-IQ's antenna input OFF whatever existing
external antenna she has WHEN I hit xmit on the K3. Call it a
precaution. Won't have anything to do with xmit on the K3 nor Rx. Just
the fact I want to externally close a relay that puts the SDR-IQ into
50-ohm lad when K3 xmit.

This is essentially what we do with some high-end Pre-amps for EME.

I was hoping somebody in the list had already solved the mechanics.


>   The IF connection on the
> K3 is only an output, so the converter will connect to one of the 
> antenna inputs to the K3.  If it is to be receive only, you could 
> connect to the RX antenna input or to the ANT1 or ANT2 connections of 
> the KAT3, or to the RX port of the KXV3.

> If the external device is to transmit as well as receive, you can 
> connect it to one of the KAT3 antenna jacks, or if it is capable of 1 mW
> IF transmit levels, connect it to the same IF connectors as used for the
> VHF/UHF transverters.

> 73,
> Don W3FPR

> On 12/16/2012 6:31 PM, KD7YZ Bob wrote:
>> Howdy K3' people:
>>
>> Here's another one I am trying to solve. What if I want to receive down
>> at 17.2KHz  sometimes ... or certainly below 4 or 500KHz, the base of
>> the K3? Well,, that connection to the IF, was handy and safe, but now I
>> need external antenna.
>>
>> Also, it is safest of when the SDR-IQ is not to the IF  that we switch
>> the SDR-IQ input to maybe a 50 ohm dummy during xmit cycle of K3.
>>
>> Anyone have this worked out? What equipment re you using and what
>> connection from K3 does the switching.
>>
>> I have sequencer's for my 6m EME pre-amp ... just wondering what anyone
>> else does with the K3?
>>
>> Actually, I need to know this anyway since the EME stuff was
>> driven/switched by my former rig, the FT-950 and I haven't figured out
>> how to switch the sequencer on K3 xmit anyway.
>>
>>
>>
>>
>>




-- 
73
KD7YZ Bob