[Elecraft] K3 Strange Power Output Problem

Sun May 13 20:17:02 EDT 2018

Hi Don, 

Fortunately I have a year to implement a solution! If worse comes 
to a worse, I could use a small external T/R relay to switch the 
antenna between K3 ANT1 and the KRX3 sub receiver AUX input... 

Is any publicly available performance data available for the low 
pass and bandpass filters in the K3 and the KBPF3? 

Its hard to devise a solution without this knowledge! 

Thanks for your help! 

73 
Frank 
W3LPL 

----- Original Message -----

From: "Don Wilhelm" <donwilh at embarqmail.com> 
To: donovanf at starpower.net, "Elecraft" <elecraft at mailman.qth.net> 
Sent: Monday, May 14, 2018 12:02:17 AM 
Subject: Re: [Elecraft] K3 Strange Power Output Problem 

Frank, 

You still have the K3 Low Pass Filters to deal with. 
The KBPF3 in the sub and the use of a separate RX antenna may produce 
better results. 

But then Wayne is the guy to say what other obstacles might be in the way. 

73, 
Don W3FPR 

On 5/13/2018 7:45 PM, donovanf at starpower.net wrote: 
> Hi Wayne, 
> 
> 
> The MARS to ham band K3 cross-band problem affects every band, 
> but it was extremely severe on 30 meters because the NSS assigned 
> frequency -- 9448 kHz -- was almost 700 kHz from our typical 
> 10128 kHz receiving frequency. 
> 
> 
> Since switching between the K3 bandpass filters and the KBPF3 
> band pass filters at T/R rates isn't a workable solution, how about 
> this external BNC cable solution since my K3 transceivers have 
> KRX3 sub receivers? 
> 
> 
> If I understand the K3 internal receiver antenna switching correctly 
> a single external BNC jumper cable allows the K3 to transmit and 
> receive on VFO A on MARS frequencies and listen to any amateur 
> band on the sub receiver: 
> 
> 
> - Connect the RX ANT OUT connector to the RX ANT IN connector 
> 
> 
> - Tap the main RX ANT button which connects ANT 1 to the RX ANT OUT 
> connector and switches the input of the main receiver to the RX ANT IN 
> connector (connected by the external BNC cable to RX ANT OUT) 
> 
> 
> - Tap SUB to turn the sub receiver on 
> 
> 
> - Hold BSET and tap ANT to set the sub receiver input to MAIN. This 
> allows the subreceiver to listen on the RX ANT connected to the main 
> receiver. 
> 
> 
> I'm sorry I didn't think of this yesterday... 
> 
> 
> tks 
> 
> 
> 73 
> Frank 
> W3LPL 
> 
> 
> 
> 
> 
> 
> 
> ----- Original Message ----- 
> 
> From: "Wayne Burdick" <n6kr at elecraft.com> 
> To: "Elecraft" <elecraft at mailman.qth.net> 
> Sent: Sunday, May 13, 2018 4:06:51 PM 
> Subject: Re: [Elecraft] K3 Strange Power Output Problem 
> 
> I have to admit, operating SPLIT between a ham band and a MARS band that falls outside the nearest ham-band filter isn’t something that occurred to me when writing the firmware. But I can change the filter selection algorithm to accommodate this case as long as a KBPF3 module is installed. 
> 
> Technical details: 
> 
> Since the K3/K3S is a downconversion superhet, we use very narrow ham-band filters. One of the narrowest is the 30 meter filter. 
> 
> To preserve the rig’s exceptional dynamic range, we switch the band pass filters with relays, not diodes. This means we can’t switch filters at T/R rates. 
> 
> So to handle the case being discussed, we’d have to select the 7-10 MHz KBPF3 filter for both RX and TX. 
> 
> 73, 
> Wayne 
> N6KR 
> 
> 
> ---- 
> http://www.elecraft.com 
> 
>> On May 13, 2018, at 6:10 AM, Wes Stewart <wes_n7ws at triconet.org> wrote: 
>> 
>> Another reading comprehension problem. 
>> 
>>> On 5/12/2018 1:36 PM, Mark E. Musick wrote: 
>>> Hi Ed, 
>>> You don't have a transmit problem at all. It is not an anomaly. 
>>> The amateur band starts at 10.100 MHz. You shouldn't be transmitting below that frequency. 
>>> 
>>> Hello, 
>>> I noticed this power output anomaly today while trying to work the NSS station. My K3 was in split mode, transmitting on 10.113.5. 
>> 
>> ______________________________________________________________ 
>> Elecraft mailing list 
>> Home: http://mailman.qth.net/mailman/listinfo/elecraft 
>> Help: http://mailman.qth.net/mmfaq.htm 
>> Post: mailto:Elecraft at mailman.qth.net 
>> 
>> This list hosted by: http://www.qsl.net 
>> Please help support this email list: http://www.qsl.net/donate.html 
>> Message delivered to n6kr at elecraft.com 
> ______________________________________________________________ 
> Elecraft mailing list 
> Home: http://mailman.qth.net/mailman/listinfo/elecraft 
> Help: http://mailman.qth.net/mmfaq.htm 
> Post: mailto:Elecraft at mailman.qth.net 
> 
> This list hosted by: http://www.qsl.net 
> Please help support this email list: http://www.qsl.net/donate.html 
> Message delivered to donovanf at starpower.net 
> ______________________________________________________________ 
> Elecraft mailing list 
> Home: http://mailman.qth.net/mailman/listinfo/elecraft 
> Help: http://mailman.qth.net/mmfaq.htm 
> Post: mailto:Elecraft at mailman.qth.net 
> 
> This list hosted by: http://www.qsl.net 
> Please help support this email list: http://www.qsl.net/donate.html 
> Message delivered to donwilh at embarqmail.com 
> 