[Elecraft] QRQ

[Geoffrey Mackenzie-Kennedy]

Jim,

The "thumping" you hear during contests could be due to overload, especially 
so if you have the IF noise blanker turned on.

The common problem with typical IF noise blankers is that they are hit by 
*all* of the signals large and small that get through the wide bandpass 
filters. If the sum total of all of these signals is large in amplitude, 
then the NB could be overloaded. Backing off the "RF" gain won't help 
because it changes the gain of the IF after the NB and roofing filter, not 
the gain before the NB. To change the gain before the K3's NB you have to 
change the preamp and attenuator settings.

NBs that do not suffer from this problem blank the LO, but that's another 
subject.

73,
Geoff
GM4ESD


Jim Miller KG0KP wrote on Wednesday, June 16, 2010 at 7:54 PM:


> OK, Guys, I'm a newbe to ham(18 years) compared.  And I have been avoiding 
> CW until the past few months (after passing my 20 word test for my 
> extra(16 years ago!)).  This spring I started Triple Play to force myself 
> to get serious on CW and it has been uphill all the way but I am gaining 
> on it (still missing 15 states CW on LOTW).
>
> QRQ?  High speed CW ??  OK, so how do you get to 60 or 100 WPM anyway?  PC 
> or at least keyboard input?  I can't imagine accuracy for copyable code 
> being input via paddle above maybe 40 wpm or so.  Also, PC for decode even 
> up to 100 wpm or is that by ear !!! ?
>
> Also, during the contests I sometimes hear cw going so fast all that is 
> heard is "thumping", there is no tone whatsoever being transmitted.  Do I 
> have something set wrong or are some radios prone to transmit like this? 
> These are not close in stations (579 or so) so it shouldn't be overload 
> and backing off the rf gain doesn't make it any different.
>
> Thanks, de Jim KG0KP