[Flexradio] Odd RFI Problem

[Dudley Hurry]

Scott,

Sounds like the printer software is causing some pretty large delays,  
and the RX thread is getting lost,  most likely because of all the 
printer reset request,  just guessing..  

I will tell you that in the future some of this will be recovered from 
with the new FireWire driver and new version of PowerSDR..  


73,
Dudley

WA5QPZ



Scott Myers wrote:
>
> I recently bought a new Ameritron AL-80B amp (as you know Dudley) and 
> realize that I have one of several problems due to RFI.
>
>  
>
> When I run on 20M or 15M and I run 100% duty cycle modes like RTTY 
> over 200 watts or so, I will get a drop out of my network connection 
> to my printer, but not the network itself.  Then just AFTER 
> transmission (not during) PowerSDR will freeze within 5 seconds.  It 
> is fixed by a quick stop/start of PowerSDR.  It is probably a 
> combination of factors, but certainly some wire length harmonic issue 
> somewhere seems to be the culprit based upon this evidence.
>
>  
>
> I already have ferrite on the shack computer's network cable.  So now 
> I need to add one to the printer's network cable, or perhaps some back 
> up at the router... or both.  I will also try repositioning my 
> commercial choke in the feedline, as it might help to move it just 
> outside the shack as opposed to inside the shack.  Lot of things to 
> try with cable lengths and chokes.  I'll put chokes on all the wires 
> that lead into the computer, including the power cable.
>
>  
>
> But what is up with the fact that PowerSDR will run fine and not 
> freeze until AFTER I end the TX?  And not until a few seconds after it 
> ends.  I can sometimes count to 5 before it freezes at ending TX!  
> This just seems odd.  I have noted I can see a bright horizontal line 
> across the waterfall in DM780 as the TX ends, as if the rig has gone 
> into RX mode before the amp actually stops transmitting.  I was 
> wondering if this could be related to the problem and somehow this 
> change in TX to RX state is with the timing of the amp shutting off 
> and is somehow overloading the firewire cable with primary RF 
> fundamentals.
>
>  
>
> There are no problems on any band except for 20M & 15M.  I may also 
> have to play with the ground system, as my main ground strap is not as 
> short as it could be.
>
>  
>
> I'll get to working on it this weekend, but any thoughts would be 
> appreciated.
>
>  
>
> 73,
>
> Scott AC8DE
>