Re: [Elecraft] [K3] AGC-OFF

[Eric Scace K3NA]

Another factor at play is the sensitivity/efficiency of the headset.  For a 
given power level, different headsets will deliver different sound levels to 
the 
ear.

In the case of my in-ear monitors, I found a significant amount of 
attenuation of the K3's headphone output was needed to:
1)  Suppress the low-level broadband hiss of the K3's audio output 
amplifier 
to a level where I could not hear it.
2)  Keep the maximum output level of the K3 (the point where the AF limiter 
kicks in) just below the "ouch" level for my ears.

A different set of headphones required much less attenuation (5-10 dB) to 
meet (2) above and the hiss couldn't be heard even without the attenuator.

A less efficient set of headphones might cause the operator to think the AF 
limiter was kicking in at way too low a level.  In this case, that pair of 
headphones might need a bit of audio amplification between the K3 and the 
earpiece.

Regarding Barry's note about long-term comfort:  custom-fitted earpieces 
for 
in ear monitors worked for me... but this is a more costly solution (but bought 
only once - hi!).  I can wear the in ear monitors for 48 hours without even 
thinking about it.  I could never do that with ordinary headphones.  But 
everyone is different!

In ear monitors that do not use custom-fitted ear pieces (i.e., use the 
rubbery or foam ear plugs) exert some pressure on the sides of the ear canal 
and 
can be annoying after 6-8 hours... at least for me.

— Eric K3NA

p.s.:  The contesting wiki has the information to which Barry referred:


on 2011 Jun 22 07:03 Barry N1EU said the following:
> Dave Hachadorian wrote:
>> There are two major problems with turning off the K3's AGC:
>>
>> 1.  There is very little dynamic headroom until the AF Limiter
>> causes severe distortion on even a moderately loud signal, even
>> if the AF Limiter setting is max.
>>
> That's not necessarily true, although probably true with most headphones on
> the market.  Assuming non-impaired hearing, the effective dynamic range will
> be highly dependent on your baseline (ambient) noise level and subsequent
> gain settings.  That's why K3NA strongly emphasized the need for high
> isolation headphone schemes in his original treatise on AGC-less contesting.
> The higher the isolation, the greater the ability to hear low audio levels,
> the lower the needed gain setting, and the greater the dynamic range before
> onset of distortion/clipping/painfully Loud levels.  With the highest
> isolation schemes, distortion/clipping rarely occurs while the weakest
> signals are still rendered audible.  I know that in-ear type phones ("ear
> buds") can be very successful in this regard, but long term comfort is
> suspect.  Every over-the-ear headphone I've tried so far that was touted as
> "high" or "extreme" isolation didn't quite deliver the degree of isolation
> that was hoped for, and weren't any better than my Sennheiser HD-280.  I'm
> still searching for more isolation without compromising comfort.
>
> 73, Barry N1EU
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Re: [Elecraft] SO-239 Concerns -- Another Perspective

[Eric Scace K3NA]

The "turn of the screw" method for tightening (used for many nut and 
bolt fasteners) is appropriate with UHF connectors: firm finger tight, 
and then use a tool (pliers) to tighten an additional quarter-turn.

If you can remove the shell without using a tool, it's too loose.

-- Eric K3NA

on 2010 Jul 23 09:23 Joel R. Hallas said the following:
> I agree with most of what has been said in support of UHF connectors for HF
> and low VHF -- with two reservations.
>
> 1. Many SO-239s provided as part of radio equipment are not up to the
> quality of Amphenol units. In particular, the spring fingers of the socket
> for the male pin loosen over time to the point that the connection becomes
> less than solid. This is particularly a problem if the connector is used
> repeatedly. I usually replace with Amphenol units, if I can get to them.
> Another great option is the Oak Hills BNC kit, designed to fit the hole
> pattern of the SO-239.
>
> 2. The other potential problem with UHF connectors, in my opinion, is the
> integrity of the shield connectivity through the connected pair. If the
> backshell loosens, there is no longer a solid connection either at the
> toothed parallel portion, nor through the backshell. This can be an issue in
> mobile or other high vibration environments and has caught me many times.
> Note that a type N, C or BNC pair makes it's shield connection through the
> inner spring tension sleeve, maintaining contact almost until the pair
> separates. The backshell is just used for mechanical, not electrical,
> purposes.
>
> FWIW
>
> Regards, Joel
> Joel R. Hallas, W1ZR
>
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Re: [Elecraft] [K3] K3NA on 5 pole vs 8 pole filters

[Eric Scace K3NA]

Gents --

   I am not sure where the misinformation began that I use 5-pole 
filters.  None of the K3s used by Radio Expeditions, and none of my 
personal K3 radios, use 5-pole filters (other than the stock filter).

   My personal filter configuration at the time I bought my radios was:
2.7 kHz stock -- TX
1.8 kHz 8-pole -- forced for all SSB receive (even if DSP is wider), CW, 
RTTY
1.0 kHz 8-pole -- CW, RTTY
0.4 kHz 8-pole -- CW, RTTY

   Radio Expeditions also includes 0.25 kHz 8-pole filters to aid in 
searching for weak signals between strong ones in pileups; e.g., for 
Ducie Island, when the band was open to Europe and we were trying to 
find the weak Europeans in between louder signals calling from North 
America.

   It is true that I run with AGC=off.  I have yet to find a combination 
of AGC settings that sounds as clear as AGC=off.  This strategy isn't 
for everyone and requires some care and discipline.
   -- I rarely do "casual listening" where AGC might even out signal 
levels for comfortable speaker monitoring.
   -- I work hard for a very quiet listening environment, so that I can 
hear 80+ dB of signal dynamic range.  With my headphones on, my noise 
floor is the sound of my own heartbeat and the blood pulsing in my ears, 
and I adjust the receiver so that the band noise is just above this level.
   -- I have an attenuator between my in-ear monitors and the radio 
headphone jack.  The K3 audio output amplifier can not deliver a loud 
enough signal into my in-ear monitors to make me go "ouch".

   The reward of this approach is an extraordinary clarity to signals, 
and no residual gain reductions caused by static crashes or loud signals 
hanging the AGC.

   [Bill W4ZV is correct: there is still gain control in front of the 
A/D converter that cannot be disabled.]

73,
   -- Eric K3NA

on 2010 May 28 15:23 Ed Muns said the following:
>> Ed Muns, W0YK wrote:
>> 
>>> Keep in mind that Eric (K3NA) typically operates with AGC off, 
>>> especially in the presence of strong signals.
>>>
>>>   
>
> Bill Tippett, W4ZV, replied:
>   
>> True but "AGC Off" only applies to the digital (DSP) AGC.  
>> Hardware AGC is always on (to protect the DSP) and therefore is
>> subject to blocking, even if AGC is set to Off.
>> 
>
> Ah, right ... fuzzy thinking.  Radio Expeditions, Inc. may have a lot of
> 5-pole filters to swap out before the next trip, hi!
>
> Ed - W0YK
>   
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[Elecraft] K3 strong signal handling

[Eric Scace K3NA]

Hi Wayne --

   I always get nervous when I see diodes proposed to clip strong RF.

   One of the biggest problems we have in a multi-transmitter site 
(DXpedition or multi-TX contest station) is IMD generated by diodes 
rectifying RF and re-radiating the result back into the local 
environment.  Even a nearby AM BC station can induce enough voltage on 
cause diodes to start rectifying.

IMHO, if some guy wants to listen to a full-power signal from <100m 
away, it is his responsibility to insert an appropriate external attenuator.

   I really don't want to see the performance of the K3 (AGC on or off) 
compromised in any way whatsoever to handle such an atypical scenario.

73,
   -- Eric K3NA
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Re: [Elecraft] Fw: Re: My K3's hissy and noisy audio

[Eric Scace K3NA]

No.  It's 3 resistors in a T or pi attenuator circuit.  There are many 
attenuator calculators on the web (just Google) to help select the 
appropriate resistors for your headphone impedance and desired amount of 
attenuation.  One attenuator is needed for each ear.

on 2009-04-05 22:14 Billy Cox said the following:
> Eric, is this a simple resistor or ?
>
> BTW, TU for the NCJ articles on TX/RX.
>
> 73 de Billy, AA4NU
>
> -Forwarded Message-
>   
>> From: Eric Scace K3NA 
>> Sent: Apr 5, 2009 9:21 PM
>> To: Maarten van Rossum 
>> Cc: Elecraft Group 
>> Subject: Re: [Elecraft] My K3's hissy and noisy audio
>>
>> I have very sensitive in-ear monitors.  The K3 (and the Orion, and 
>> possibly other radios) has significant hiss.  I inserted an attenuator 
>> and knocked the hiss down below my ability to detect it.  There is 
>> plenty of audio range remaining.
>>
>> You may find 10 to 20 dB will help.
>> 
>
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Re: [Elecraft] My K3's hissy and noisy audio

[Eric Scace K3NA]

I have very sensitive in-ear monitors.  The K3 (and the Orion, and 
possibly other radios) has significant hiss.  I inserted an attenuator 
and knocked the hiss down below my ability to detect it.  There is 
plenty of audio range remaining.

You may find 10 to 20 dB will help.
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[Elecraft] Elecraft K3/K2 <-> microHam cable set for sale

[Eric Scace K3NA]

Hi --

   I have an extra microHam cable set for the Elecraft K3 or K2 
available (DB37-EL-K3).  List price for a new cable is US$79 + shipping.

   I will sell for $60 + shipping.

   Please contact me directly -- please don't respond to the whole 
list!  Thanks.

73,
   -- Eric K3NA


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[Elecraft] K3 birdies - question?

[Eric Scace K3NA]

Hi David --

   It was my oversight not to sent the concept to the reflector.

   However I will note that it takes a substantial amount of ferrite to 
develop serious Z at HF.  I'm skeptical that a few beads at each end 
will have a material effect... but perhaps someone will give it a go and 
report a result.

   I also must recognize that the idea leakage is picked up on the 
shield and conducted to an undesirable location is also speculative.  If 
pickup is coming from the KREF or KSYN boards, then another approach 
would be to place a shield around the offending (radiating) board.  But 
that's a more complex task to try and raises issues of heat capture.

-- Eric

 Original Message 
Subject:Re: [Elecraft] K3 birdies - question?
Date:   Thu, 5 Mar 2009 17:19:34 -
From:   David Cutter 
To: 
References: 
<20090305102431.7oc8p.948859.r...@web08-winn.ispmail.private.ntl.com> 
<49affc5c.8050...@k3na.org>



Eric

That's an even better idea.  The tiny connector on the end will allow quite 
a small bead/tube to be used.  This can then be taped or heat shrink and 
somehow supported to stop it clunking about.

Thanks for the idea, why not put it on the reflector?

David
G3UNA

- Original Message ----- 
From: "Eric Scace K3NA" 
To: 
Sent: Thursday, March 05, 2009 4:22 PM
Subject: Re: [Elecraft] K3 birdies - question?


>I wonder if a string of suitable ferrite beads would be enough Z to kill 
>anything on the shield of these short cables.  One would need to protect 
>the ferrite from touching the circuit boards...
>
> on 09 Mar 05 05:24 d.cut...@ntlworld.com said the following:
>> So, could we use the good old methods of wrapping the coax around a 
>> suitable toroid.  That would mean a longer cable at which point I would 
>> invest in a better quality cable if I were doing it and I'm tempted to do 
>> so to get the best chance of cracking the main issues we are addressing.
>>
>> David
>> G3UNA
>>
>>  Geoffrey Mackenzie-Kennedy  wrote:
>>> David,
>>>
>>> Double shielded coax would certainly reduce leakage from the coax, and 
>>> is a good investment in my opinion. However its use might not have too 
>>> much impact on the receiver's birdie problem, because many of the 
>>> "rogue" signals involved are probably flowing on the outside of the 
>>> coax's braid, certainly if the coax emerges from some enclosure through 
>>> a hole.
>>>
>>> The usual cause of a receiver birdie is that some response of the 
>>> receiver is "hearing" some oscillator or a harmonic, or some mixing 
>>> product of two or more oscillators, contained within the receiver. In a 
>>> down conversion HF receiver, the great majority of the receiver's 
>>> responses, therefore the "rogue signals", that cause birdie problems are 
>>> at HF and up to low/ mid VHF, which means that choking off coax runs 
>>> within a receiver becomes cumbersome.
>>>
>>> 73,
>>>
>>> Geoff
>>> GM4ESD
>>>
>>> David Cutter wrote on Wednesday, March 04, 2009, at 10:32 AM:
>>>
>>>
>>>> I also wonder if it would be worthwhile buying higher spec coax.  Don't 
>>>> know what is used in the K3, but for the lengths involved it would be 
>>>> worth the investment to get short cables made in say LMR100 or RG142 
>>>> etc if it's not already
>>>>
>>>> David
>>>> G3UNA
>>>>
>>> 


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Re: [Elecraft] K3 Transmit thru Line-In

[Eric Scace K3NA]

Did you set the Line In gain control to a value >0?

on 09 Mar 05 10:43 Bud Governale, W3LL said the following:
> I can't get any transmit audio via the Line-In connector.
>
> Connecting the Mic cable to the rear panel MIC connection produces good 
> transmit power and audio.
>
> I know audio is coming from the sound card output because it also drives the 
> computer speaker via its line in 
> connection.
>
> I tried moving the Mic connector from the rear panel MIC to the Line-In rear 
> panel position. This still would not 
> produce K3 SSB output.
>
> Moving the Line-In connector to the MIC rear panel connector produces good 
> transmit power and audio.
>
> The TX lights each time but no output via Line-In
> The K3 is in LSB mode.
> TX TEST is in normal.
> MIC SEL is RPH
> MIC + LIN is ON.
> MIC Gain is 30
> Comp is 22.
>
> Why can't I transmit thru the Line-In connection?
>
> 73,
>
> Bud W3LL
> w...@arrl.net
>
>
>
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Re: [Elecraft] [Elecraft_K3] RE: K3+microKeyer+MM: Realtek AC'97 feedback

[Eric Scace K3NA]

Thanks, Joe, Lyle and Tim (KT1D).  It was indeed the Playback Line In 
control being un-muted.  Now on to the next problem.

The tip to update the Router presets was especially valuable!

on 09 Mar 03 19:27 Joe Subich, W4TV said the following:
>> I suspect (but do not know) that it is the PC mixer configuration.
>> 
>
> I agree with Lyle ... the computer is almost certainly echoing Line 
> In to Line Out.  Right click on the task bar speaker Icon and 
> select "open Volume Control."  Select options | Properties | Playback 
> and the miser device for the soundcard to which microKEYER/K3 is 
> connected.  Look to see if Line In is one of the "Volume controls" 
> options ... enable it and click "OK."  Now, make sure the Line IN 
> level is all the way down and that channel is muted (note Line IN 
> may be identified by the color of its jack).  Update Router's presets 
> so the Line In is always muted on the playback side. 
>
> microKEYER does not have any ability to connect Line In to Line Out. 
>
> 73, 
>
>... Joe, W4TV 
>  
>
>
>
>
>   
>> -Original Message-
>> From: elecraft-boun...@mailman.qth.net 
>> [mailto:elecraft-boun...@mailman.qth.net] On Behalf Of Lyle Johnson
>> Sent: Tuesday, March 03, 2009 6:26 PM
>> To: e...@k3na.org
>> Cc: Joe Subich W4TV; Elecraft mailing list; N1MM Logger; 
>> supp...@elecraft.com; Elecraft K3 mailing list
>> Subject: Re: [Elecraft] K3+microKeyer+MM: Realtek AC'97 feedback
>>
>>
>> Hello Eric!
>>
>> 
>>>I'm seeking advice on a feedback problem.
>>>
>>>Scenario:
>>> PC line out -> microKeyer -> K3 mic in (Note 5)
>>> PC line in <- K3 line out.  (Note 1)
>>>Note 1:  microKeyer is bypassed so that stereo gets delivered to 
>>> the
>>> computer for archival recordings.
>>>Note 2:  K3 CONFIG: LIN OUT can be either "nor 001" or "=phones" 
>>> without changing the problem.
>>>Note 3:  To simplify and isolate the problem, MM is not running.
>>>Note 4:  More details about the PC and K3 firmware listed below.
>>>Note 5:  Can connect direct to K3 Line In (bypassing the 
>>>   
>> microKeyer), 
>> 
>>> changing MENU MIC SEL accordingly, without affecting the problem.
>>>
>>>When I put the radio into TX (short the footswitch input on the
>>> microKeyer), and play an audio file out the PC, a feedback 
>>>   
>> loop exists.  
>> 
>>> The severity of the loop depends on the K3 MON setting: low setting 
>>> (<<10) means no echo chamber.
>>>
>>>The only possibilities are the K3 is making the loop, or the 
>>> computer
>>> is making the loop.  I'm not sure how to isolate this.
>>>   
>> I suspect (but do not know) that it is the PC mixer configuration.
>>
>> If the K3 is outputting MON audio, then what appears at the 
>> K3 LINE IN 
>> will re-appeer at K3 LINE OUT with some delay and +/- gain. 
>> If the PC's 
>> mixer is active so that the PC LINE IN is mixed with whatever 
>> source you 
>> are playing back, then you'll probably get feedback.
>>
>> One way to tell is to remove the K3 and just loop the PC 
>> output back to 
>> its input.  You might want to listen on an amplified speaker using Y 
>> cable - or not, depending on how much you value your hearing :-)
>>
>> 73,
>>
>> Lyle KK7P 
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>
>
> 
>
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[Elecraft] K3+microKeyer+MM: Realtek AC'97 feedback

[Eric Scace K3NA]

Hi --

   I'm seeking advice on a feedback problem.

   Scenario:
PC line out -> microKeyer -> K3 mic in (Note 5)
PC line in <- K3 line out.  (Note 1)
   Note 1:  microKeyer is bypassed so that stereo gets delivered to the 
computer for archival recordings.
   Note 2:  K3 CONFIG: LIN OUT can be either "nor 001" or "=phones" 
without changing the problem.
   Note 3:  To simplify and isolate the problem, MM is not running.
   Note 4:  More details about the PC and K3 firmware listed below.
   Note 5:  Can connect direct to K3 Line In (bypassing the microKeyer), 
changing MENU MIC SEL accordingly, without affecting the problem.

   When I put the radio into TX (short the footswitch input on the 
microKeyer), and play an audio file out the PC, a feedback loop exists.  
The severity of the loop depends on the K3 MON setting: low setting 
(<<10) means no echo chamber.

   The only possibilities are the K3 is making the loop, or the computer 
is making the loop.  I'm not sure how to isolate this.

   Anyone else see/solved this?

   It's not life-critical, but it means no audio archive for the ARRL DX 
Phone contest if I can't solve it.

   Thanks.

-- Eric K3NA

K3 FW: 2.78
PC:  Shuttle SN41
Chipset:  Realtek with AC'97 drivers
Op sys:  Win XP SP3
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Re: [Elecraft] K3 receiver desensing on CW during contest

[Eric Scace K3NA]

At the W1KM contesting site, we routinely see signals of +5 dBm or 
louder on/near 40m from SWBC stations (using a single Yagi).  We also 
have two modest-power local AM stations (1 to 5 kW, a few miles away) 
just below 1500 kHz that show up even a bit stronger than that on our 
160m antennas.

Without taking into consideration signals from our own multi-multi 
transmitters, a receiver is already faced with >>130 dB range between 
weak signals on 160m in mid-afternoon arriving from Europe and these 
other signal sources.

WD3Q, a contester in Washington DC, has much stronger AM BC stations to 
deal with, including a 50 kW station on 1500 kHz.

Wide-open receiver front ends attached to an A/D converter are not yet 
viable for these locations.

-- Eric K3NA

on 09 Feb 24 20:44 N8LP said the following:
> You may be right, Al. I think the improvements may be incremental, and
> distributed among various aspects of the design, not just the ADC. For
> instance, ultra-low jitter clock sources, faster FPGAs with improved IP
> cores, etc. I think most hams would be thrilled with an improvement to 130dB
> BDR, along with getting rid of phase distortion, ringing and other anomalies
> in the xtal filters and other analog components. Unless you live near a
> shortwave broadcast station, or have a high power ham nearby on the same
> band, you're not likely to need 130dB BDR anyway. Even in those cases,
> having 200dB BDR probably wouldn't help unless there is a LOT of improvement
> in transmitter spurious emissions, distortion and phase noise. 
>
> The highest signals I have seen here, during Field Day when there were
> several stations operating within a few miles of me, were <120dB above the
> noise floor. Of course, it's very important not to use any more front end
> gain than necessary for the band/conditions.
>
> 73,
> Larry N8LP
>   
>
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Re: [Elecraft] K3 Hardware

[Eric Scace K3NA]

Mechanical engineers refer to the "turn of the screw" method for 
tightening.  With a little practice one easily notices when the force 
required to turn the screwdriver further begins to ramp up more 
quickly.  [This point is past "finger tight", which often doesn't 
compress the lockwasher very much (if at all).]

When that ramp-up starts, go one-quarter turn further to reach the 
design load point.

This also works on the big bolts used on bridges and other ironwork.

on 09 Feb 19 15:20 K9ZTV said the following:
> I was always taught the rule is . . . "finger-tight" not "wrist-tight."
>
> The two are distinctly different.
>
> 73,
>
> Kent  K9ZTV
>
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[Elecraft] ant port isolation

[Eric Scace K3NA]

FYI --

   I made a quick test of antenna port isolation on a K3 here to look 
for a benchmark.

Main RX:
   Signal injected at RX IN BNC connector of -98 dBm.
   Pre-amp on.
   160m 1820 kHz: When the main RX was switched to Ant1 or Ant 2, and 
additional 64 dB of signal was needed to get equivalent output.
   10m 29750 kHz: When the main RX was switched to Ant1 or Ant 2, and 
additional 41 dB of signal was needed to get equivalent output.

These 64 and 41 dB isolation figures are typical for a single stage 
relay switching matrix.

When I have time, I'll do the same for the sub-RX.

-- Eric K3NA
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Re: [Elecraft] OT: VP6DX Ducie Island

[Eric Scace K3NA]

Hi everyone --

   I got a number of emails from folks lacking cards.  I will add them 
to the work queue.

   Unfortunately this week is not a good week to work on QSL cards.  We 
have an IRS filing due, and have to get a shipment to Germany (that is 
overdue).  It will probably be next week before a significant progress 
is made on QSL inquiries.

73,
   -- Eric K3NA

on 09 Jan 05 15:46 S Sacco said the following:
> Does anyone know how to contact an actual human being who could help 
> me with my VP6DX QSL request?
>  
> I've had cards pending with them since they completed their ops - and, 
> yes, I did contribute $$ to their efforts.
>  
> I've tried their website twice over the last couple of months, with no 
> luck.
>  
> Please reply directly to me, rather than the reflector.
>  
> Thanks/73
> Steve
> NN4X
> Saint Cloud, FL
> 
>
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Re: [Elecraft] K3 - LO CUT/HI CUT bugs

[Eric Scace K3NA]

A potentially related question / mis-understanding is the interaction 
between width, shift, lo and hi.  I'm not sure my concept is correct...


Firstly, people talk about 5 frequencies or ranges:
  Fc = audio center of the passband
  Fhi = -3 dB point above Fc
  Flo = -3 dB point below Fc
  Fshift
  Fwidth = passband width between -3 dB points
but I think there are also two other frequencies:
  Ffloor = lowest permitted frequency for a -3 dB point.  Let's assume 
this is 100 Hz.
  Fanchor = a reference frequency that is a conceptual point-of-return 
for the center.  In CW this is Fspot and in sideband this is a passband 
center when the passband is narrow enough that the lower edge is above 
Ffloor.


CW example:
  Start with a spot of 400 Hz and a filter setting of 500 Hz.
  Fc = 400 Hz
  Fanchor = Fspot = 400 Hz
  Flo = 150 Hz
  Fhi = 650 Hz
  Fshift = 0
  Fwidth = 500 Hz
Under my mental picture, Shift moves the passband away from the Fspot 
(Fanchor).  A shift of +100 Hz to move away from adjacent QRM changes 
the picture to:

  Fshift = +100.  Fwidth = 500 Hz
  Fanchor = Fspot = 400 Hz (unchanged)
  Fc = 500 Hz
  Flo = 250 Hz
  Fhi = 750 Hz
If one attempts to shift -100 Hz, Flo runs into the Ffloor value.  Since 
the operator presumably is trying to evade QRM on the high side, what 
should be done?  One approach is to allow the passband to narrow:

  Fshift = -100
  Fanchor = Fspot = 400 Hz
  Flo = 100 Hz (stopped at the floor)
  Fhi = 550 Hz
  Fc = 325 Hz
  Fwidth = 450 Hz.

SSB example:
  Start with 2.8 kHz width, with -3 dB points of 200 and 3000 Hz.
  Flo = 200 Hz
  Fhi = 3000 Hz
  Fc = 1600 Hz
  Fwidth = 2.8 kHz
  Fshift = 0
  Fanchor = 1600 kHz (reference point for the shift)
Now suppose one wants to operate in a contest environment.  Set the 
radio to always use a 1.8 kHz filter.  But, rather than listen to a 
too-low range of 200 - 2000 Hz, center the passband around 1600 Hz:

  Flo =700 Hz
  Fhi = 2500 Hz
  Fc = 1600 Hz
  Fwidth = 1800 Hz
  Fshift = 0
  Fanchor = 1600 Hz
Now increase the width control to 2200 Hz.  The signal still passes 
through the 1.8 kHz filter.  So the parameters are:

  Flo = 500 Hz
  Fhi = 2700 Hz
  Fc = 1600 Hz = Fanchor
  Fwidth = 2200 Hz
  Fshift = 0
This sounds quite acceptable in a contest: very intelligible but not 
troubled as much by adjacent stations as the wider crystal filter 
choices.  Manipulating the shift, width, lo and hi frequencies allow 
deviations from the above... but zeroing the shift always returns Fc to 
the anchor frequency.


  I don't think the radio quite works this way.  And maybe this isn't 
the correct model.  But hopefully it's a constructive addition to the 
conversation.


-- Eric K3NA



on 08 Nov 26 Wed 15:06 Lyle Johnson said the following:

Hello Joe!

Up until recently, I had only used the SHIFT/WIDTH functions for 
setting the DSP filter parameters.  This morning I decided to try the 
LO CUT/HI CUT functions.  I really don't understand the behavior I'm 
seeing and I suspect there's something wrong...


These oddities aren't apparent in normal day-to-day operation, but I 
think they're pretty clearly unintended.


Thank you for your investigation and detailed observations of this. 
We've taken note of it and put it "on the list" to be corrected.


Hope you have a great Thanksgiving Holiday!

73,

Lyle KK7P


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Re: [K3] [Elecraft] FLx GN Adding Db gain

[Eric Scace K3NA]

I've looked at three 400 Hz filters to date and values do vary from 
filter to filter; one of mine required 6 dB gain.  Other 8-pole filter 
bandwidths also vary a bit as well.


Just measure all the filters in the radio and true up the gains.  Don't 
need to worry about what the actually gain numbers are, as long as they 
can be goosed up to a uniform level.


on 08 Nov 11 Tue 10:44 [EMAIL PROTECTED] said the following:

Hi Ken,


The 2 dB number is bogus, in my opinion/experience.


At least for me the 2dB recommendation for the 400Hz hit the nail 
right on the head. But on the other hand, I am not much of CW man.


vy 73 de toby

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Re: [Elecraft] re ON-OFF on K3

[Eric Scace K3NA]

  The need to manually press the power button to turn on the radio is a 
problem in remote-controlled stations.  If power fails, one must visit 
the site to power up the radios.


That said, there are often many transients when power is first restored.

An ideal solution would have these attributes:
  -- if the radio was powered up when the +13 Vdc supply voltage 
disappeared, then...

  -- when +13 Vdc reappears, wait 3 seconds, and then power-up the radio.

73,
  -- Eric K3NA
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Re: [Elecraft] K3: too easy to overwrite dial memories

[Eric Scace K3NA]

  In the world of ergonomics and man-machine interface design, there is 
a rule:  If an action will destroy information  or a state than cannot 
be restored with the same effort that it took to destroy, then the 
system requires either (a) a "Un-Do" function of equal simplicity, or 
(b) a confirmation step.


  The choice between (a) or (b) depends on the consequences of the 
unintended action during the time it takes to recover.  For example, a 
(hypothetical!) button that shuts down the jet engines on an aircraft 
requires a confirmation step... because turning off the engines until 
the pilot hits UnDo would be bad!


  This rule applies to software as well as hardware.

-- Eric K3NA
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Re: [Elecraft] Soldering after Crimping

[Eric Scace K3NA]

  At the W1KM station we have had Anderson PowerPole connectors in 
service for about 4 years.  All were installed with the proper crimping 
tool.  The crimps were not soldered.


  We are starting to see some increase in resistance on some of the 
connections, and have speculated that some oxidation is occurring inside 
the crimped bundle of wires.  Typically 5 connections exist between 
source and sink:
  -- inside the power supply, between the board's wiring harness and 
the external terminal.
  -- between the supply's external terminal and a cable run toward the 
operating position.
  -- at the other end of this cable run, where it connects to a 
RigRunner (PowerPole).
  -- at the start of a second cable run, where it connects to the 
RigRunner.
  -- at the other end of this second cable run, where it connects to 
the radio.
The resistance of these connection, plus cable resistance and current 
draw, determine the voltage drop between supply and the radio's connector.


  To me, it seems a reasonable precaution to allow solder to be wicked 
up into the crimp from the front (not the rear) of the PowerPole pin.  
Properly done, this does not melt insulation nor cause the wire outside 
the housing to stiffen.


73,
  -- Eric K3NA
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[Elecraft] Re: VP6DX -- the true story ?

[Eric Scace K3NA]

Hi Dave --

  There is a lot of information about hearing available on the web.  As 
always, one should cross-check sources and exercise some skepticism.


  Hearing is logarithmic.  Turning down the gain makes it more likely 
that signals will stay below the triggering threshold for the 
attenuation reflex, so signals will remain more "different" in strength.


  Frequency discrimination, in Hz, is better at lower frequencies than 
at higher frequencies.  The optimum point for greatest frequency 
discrimination depends on the individual.  Mine is around 400 Hz.  Some 
people are lower, some higher... but 400-500 Hz is a good starting 
point.  Hearing is less sensitive (and dynamic range is a little 
smaller) at lower frequencies, so there are tradeoffs.  There was an 
on-line test for frequency discrimination available on the web... so try 
a search.


73,
  -- Eric K3NA

on 08 Mar 14 Fri 11:58 dave said the following:

Eric,

Where could one learn more about this very valuable, if arcane, 
subject?  Human hearing, that is, and how it relates to picking out 
signals.


I've long turned my volume down to aid in picking out signals.  They 
seem to "pop" out of the noise much better at low volumes than at 
high.  I've attributed this to the greater sensitivity of the ear at 
low volumes than at high, but that may not be correct.  My 
understanding is that he ear is logarithmic, the louder the sound, the 
lower the ear response.


Also, are you suggesting that we'd help ourselves in picking out weak 
ones by raising the pitch of our CW tone?  I kinda prefer the lower 
tones, but your comments seem to say that higher pitch, if we could 
stand it, would be better.


Thanks for the very interesting comments.  Postings such as your's are 
why I continue to subscribe to the list - in spite of all the "noise" 
here, hee hee!



73 de dave
ab9ca





Eric Scace K3NA wrote:

Igor --

  Your question about DSP is an interesting one.

  In my limited understanding of the K3 signal path, there is always 
a DSP operation on the signal for filtering.   While noise blanking, 
noise reduction, and audio effects can all be switched off, I don't 
know if it is possible to remove ALL digital signal processing from 
the signal path; i.e., operate only with the crystal filters.


  We certainly had plenty of marginal openings where we were required 
to work a pileup of signals just at the level of the underlying 
band/antenna noise.  But... the antenna/band noise were a significant 
step above the receiver's underlying noise floor (10 dB)... or one 
turned on the pre-amp to bring the band/antenna noise above the 
underlying receiver noise floor.  In this case, the pileup was not at 
the receiver's MDS level.


  Furthermore, the operating positions were not equipped with a 
second, different receiver and associated switching so that the 
operator could do a real-time A/B comparison between the K3 and 
"Brand X".


  Yes, signal range could be from S1 (or less) to S9+40 dB, so more 
than 90 dB.  However, several other aspects of human hearing come 
into play:


  1.  The most sensitive part of audio spectrum for typical hearing 
is 2 to 5 kHz.  If we take a K3 with very wide filters, and no 
antenna, in an extremely quiet listening environment, and just 
gradually advance the audio gain until we can just begin to hear the 
receiver noise floor, we will be listening to a higher-pitch hiss in 
this range of 2 to 5 kHz.  White noise at lower frequencies won't be 
perceptible yet until the receiver gain is advanced another 10 dB (at 
which point frequencies down to 500 Hz are audible) or 20 dB (good 
for frequencies down to 250 Hz).
  If we narrow the receiver bandwidth so we are only listening to 
100-700 Hz, for example, the receiver noise floor will appear about 
10 dB louder (relative to the minimum threshold of hearing) at the 
higher end.


  2.  Another frequency-sensitive aspect of human hearing is the 
attenuation reflex.  This reflex tightens two muscles in the ear, one 
of which tightens the ear drum slightly and the other moves the three 
bones of the middle ear to reduce the transmission to the cochlea 
(inner ear).  This is our own, human protective AGC.
  The attenuation reflex begins to act at 65-70 dB above the 
threshold of hearing at 200 Hz... but 80 dB above the threshold of 
hearing at 700 Hz.
  The "slope" of the attenuation reflex is about -0.6; i.e., a signal 
that is 18 dB above the attenuation reflex threshold will be reduced 
to just 6 dB above that threshold (i.e., 12 dB attenuation added) by 
the time it reaches the inner ear.


  Now let's look at an operator listening to a K3 in a perfectly 
quiet listening environment (no other local sounds).  If he adjusts 
the receiver so that antenna/band noise is 5 to 10 dB above his 
threshold of hearing at a pitch of 400 Hz, and then tunes across a CW 
signal that 

Re: [Elecraft] re: VP6DX

[Eric Scace K3NA]

Doug, Dan, et al --

  On Ducie Island we had a 9.6 kbit/s dial-up Internet connection with 
long latency.  Actual throughput was substantially less than this.  1-2 
kbit/s would be a good estimate.


  We could have downloaded new firmware, if we felt it was critical to 
do so.  We did not feel that any aspect of K3 behavior warranted taking 
the time to:

  -- download new firmware;
  -- interrupt an operator to install it on one radio for a "soak test" 
to make sure it didn't introduce any problems; and, if all seemed well,
  -- interrupting six other operators to install the firmware on their 
radios.


73,
  -- Eric K3NA


on 08 Mar 16 Sun 10:56 Doug Faunt N6TQS +1-510-655-8604 said the following:

Elecraft has done everything necessary to allow this.  It's up to the
DXpedition and their priorities.  I've got to say, any trip I've been
on has had the capability.

73, doug

   From: "Dan Barker" <[EMAIL PROTECTED]>
   Date: Sun, 16 Mar 2008 08:05:36 -0400

   You'd think they'd have some way to communicate a small zip file to an
   Island. It's possible a future Dxpedition might desperately need an
   firmware. They must have had a laptop along. Planning for this may help
   some day (or not).

   Dan / WG4S / K2 #2456 


   -Original Message-
   From: [EMAIL PROTECTED]
   [mailto:[EMAIL PROTECTED] On Behalf Of wayne burdick
   Sent: Monday, March 10, 2008 12:14 PM
   To: Elecraft Reflector
   Subject: [Elecraft] re: VP6DX 


   
   Several issues have already been addressed by later revisions of 
   firmware. They were not in a position to load new firmware from Ducie 
   Island, and were a few revisions behind by the time they started the 
   operation.

   

  

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Re: [Elecraft] VP6DX -- the true story ?

[Eric Scace K3NA]

Hi David --

  Thanks for your interest in this arcane subject.

  When a signal just a little bit above the trigger point for the 
attenuation reflex appears, it takes about 150 ms before attenuation 
develops.  For a very strong signal, the reflex is faster (25-35 ms) but 
there is still a period when the full power of the signal slams all the 
way through to the inner ear.


73,
-- Eric K3NA

on 08 Mar 14 Fri 06:07 David Cutter said the following:

Eric

Absolutely fascinating and confirms many years of my own experience 
and suspicions.


Am I right that the ear having shut down for a loud noise, takes a few 
ms to recover?  So, a static crash doesn't just cover the signal for 
the period of the crash but also for a short period thereafter due to 
our hearing AGC.


I suspect that, ideally, our headsets should be preceded with a peak 
limiter calibrated to the headset sensitivity to limit peak sound 
pressure into our ears to prevent  *any* natural AGC.


David
G3UNA

snip
  Yes, signal range could be from S1 (or less) to S9+40 dB, so more 
than 90 dB.  However, several other aspects of human hearing come 
into play:


  1.  The most sensitive part of audio spectrum for typical hearing 
is 2 to 5 kHz.  If we take a K3 with very wide filters, and no 
antenna, in an extremely quiet listening environment, and just 
gradually advance the audio gain until we can just begin to hear the 
receiver noise floor, we will be listening to a higher-pitch hiss in 
this range of 2 to 5 kHz. White noise at lower frequencies won't be 
perceptible yet until the receiver gain is advanced another 10 dB (at 
which point frequencies down to 500 Hz are audible) or 20 dB (good 
for frequencies down to 250 Hz).
  If we narrow the receiver bandwidth so we are only listening to 
100-700 Hz, for example, the receiver noise floor will appear about 
10 dB louder (relative to the minimum threshold of hearing) at the 
higher end.


  2.  Another frequency-sensitive aspect of human hearing is the 
attenuation reflex.  This reflex tightens two muscles in the ear, one 
of which tightens the ear drum slightly and the other moves the three 
bones of the middle ear to reduce the transmission to the cochlea 
(inner ear). This is our own, human protective AGC.
  The attenuation reflex begins to act at 65-70 dB above the 
threshold of hearing at 200 Hz... but 80 dB above the threshold of 
hearing at 700 Hz.
  The "slope" of the attenuation reflex is about -0.6; i.e., a signal 
that is 18 dB above the attenuation reflex threshold will be reduced 
to just 6 dB above that threshold (i.e., 12 dB attenuation added) by 
the time it reaches the inner ear.


  Now let's look at an operator listening to a K3 in a perfectly 
quiet listening environment (no other local sounds).  If he adjusts 
the receiver so that antenna/band noise is 5 to 10 dB above his 
threshold of hearing at a pitch of 400 Hz, and then tunes across a CW 
signal that is +95 dB above the band/antenna noise floor, that CW 
signal will be about 100 to 105 dB above the threshold of hearing.


  That signal will also be about 30 dB above the threshold for 
triggering the attenuation reflex.  At a slope of -0.6, the 
attenuation reflex will cut that signal down by 20 db... so that it 
is now 80-90 dB above the threshold of hearing.  -20 dB of 
attenuation is about the maximum the attenuation reflex can deliver 
-- but that is only in children and teenagers.  For adults, the 
maximum attenuation level declines with age, so I (at age 55) can no 
longer get -20 dB of protective attenuation. Maybe I get 10-15 dB of 
attenuation, leaving the CW signal at something like 95 dB above the 
threshold of hearing.  Of course, once this attenuation reflex is 
activated, that very weak CW signal down near the noise level will be 
attenuated below the threshold of hearing, so no more copy.


  Even worse, long exposure to signals above the attenuation reflex 
threshold results in incremental and permanent hearing damage.  So 
that CW signal, at 95 dB above the threshold of hearing... and 20 dB 
above the attenuation reflex threshold... represents an important 
hazard.  The USA National Institute for Occupational Safety and 
Health has set a limit of about 1 hour per day at this level... and 
that limit declines quickly at higher levels.


 3.  Fortunately, by setting the receiver gain at these low levels, 
that loud CW signal is below the threshold of pain (about 110 dB 
above the threshold of hearing at 400 Hz).  The threshold of pain is 
where the operator rips off the headphones and says "ouch"!  We want 
our receivers to limit signals (or static crashes) before they reach 
this level!


  So, we can't use a receiver that is perfectly linear over a 130 dB 
range -- it would destroy our hearing!  But we need to listen to 
signals in a very quiet listening environment, as quiet as we can 
get... and set the gain levels appropriately... and use some form of 
signal limiting to keep signals well below t

Re: [Elecraft] VP6DX -- the true story ?

[Eric Scace K3NA]

Igor --

  Your question about DSP is an interesting one.

  In my limited understanding of the K3 signal path, there is always a 
DSP operation on the signal for filtering.   While noise blanking, noise 
reduction, and audio effects can all be switched off, I don't know if it 
is possible to remove ALL digital signal processing from the signal 
path; i.e., operate only with the crystal filters.


  We certainly had plenty of marginal openings where we were required 
to work a pileup of signals just at the level of the underlying 
band/antenna noise.  But... the antenna/band noise were a significant 
step above the receiver's underlying noise floor (10 dB)... or one 
turned on the pre-amp to bring the band/antenna noise above the 
underlying receiver noise floor.  In this case, the pileup was not at 
the receiver's MDS level.


  Furthermore, the operating positions were not equipped with a second, 
different receiver and associated switching so that the operator could 
do a real-time A/B comparison between the K3 and "Brand X".


  Yes, signal range could be from S1 (or less) to S9+40 dB, so more 
than 90 dB.  However, several other aspects of human hearing come into play:


  1.  The most sensitive part of audio spectrum for typical hearing is 
2 to 5 kHz.  If we take a K3 with very wide filters, and no antenna, in 
an extremely quiet listening environment, and just gradually advance the 
audio gain until we can just begin to hear the receiver noise floor, we 
will be listening to a higher-pitch hiss in this range of 2 to 5 kHz.  
White noise at lower frequencies won't be perceptible yet until the 
receiver gain is advanced another 10 dB (at which point frequencies down 
to 500 Hz are audible) or 20 dB (good for frequencies down to 250 Hz).
  If we narrow the receiver bandwidth so we are only listening to 
100-700 Hz, for example, the receiver noise floor will appear about 10 
dB louder (relative to the minimum threshold of hearing) at the higher end.


  2.  Another frequency-sensitive aspect of human hearing is the 
attenuation reflex.  This reflex tightens two muscles in the ear, one of 
which tightens the ear drum slightly and the other moves the three bones 
of the middle ear to reduce the transmission to the cochlea (inner 
ear).  This is our own, human protective AGC.
  The attenuation reflex begins to act at 65-70 dB above the threshold 
of hearing at 200 Hz... but 80 dB above the threshold of hearing at 700 Hz.
  The "slope" of the attenuation reflex is about -0.6; i.e., a signal 
that is 18 dB above the attenuation reflex threshold will be reduced to 
just 6 dB above that threshold (i.e., 12 dB attenuation added) by the 
time it reaches the inner ear.


  Now let's look at an operator listening to a K3 in a perfectly quiet 
listening environment (no other local sounds).  If he adjusts the 
receiver so that antenna/band noise is 5 to 10 dB above his threshold of 
hearing at a pitch of 400 Hz, and then tunes across a CW signal that is 
+95 dB above the band/antenna noise floor, that CW signal will be about 
100 to 105 dB above the threshold of hearing.


  That signal will also be about 30 dB above the threshold for 
triggering the attenuation reflex.  At a slope of -0.6, the attenuation 
reflex will cut that signal down by 20 db... so that it is now 80-90 dB 
above the threshold of hearing.  -20 dB of attenuation is about the 
maximum the attenuation reflex can deliver -- but that is only in 
children and teenagers.  For adults, the maximum attenuation level 
declines with age, so I (at age 55) can no longer get -20 dB of 
protective attenuation.  Maybe I get 10-15 dB of attenuation, leaving 
the CW signal at something like 95 dB above the threshold of hearing.  
Of course, once this attenuation reflex is activated, that very weak CW 
signal down near the noise level will be attenuated below the threshold 
of hearing, so no more copy.


  Even worse, long exposure to signals above the attenuation reflex 
threshold results in incremental and permanent hearing damage.  So that 
CW signal, at 95 dB above the threshold of hearing... and 20 dB above 
the attenuation reflex threshold... represents an important hazard.  The 
USA National Institute for Occupational Safety and Health has set a 
limit of about 1 hour per day at this level... and that limit declines 
quickly at higher levels.


 3.  Fortunately, by setting the receiver gain at these low levels, 
that loud CW signal is below the threshold of pain (about 110 dB above 
the threshold of hearing at 400 Hz).  The threshold of pain is where the 
operator rips off the headphones and says "ouch"!  We want our receivers 
to limit signals (or static crashes) before they reach this level!


  So, we can't use a receiver that is perfectly linear over a 130 dB 
range -- it would destroy our hearing!  But we need to listen to signals 
in a very quiet listening environment, as quiet as we can get... and set 
the gain levels appropriately... and use some 

Re: [Elecraft] VP6DX -- the true story ?

[Eric Scace K3NA]

Privet Igor --

  As best I can remember, we used MCU v1.66 and DSP 1.52.

  I didn't use the AGC because I did not need it.  The point of 
automatic gain control is to adjust the gain of the various stages of 
the receiver in order to

  a) avoid distortion/overdriving a stage, and
  b) bring signals up/down to a comfortable listening level.

  (b) is not relevant to an operator who is working a pileup.  (b) is 
relevant to an operator who is monitoring a frequency with one station 
transmitting.


  For operating a pileup, there are a variety of tools the brain uses 
to distinguish the many signals:

  -- pitch (CW)
  -- style of speaking (speech) or keying (CW)
  -- artifacts; e.g., auroral flutter, chirp, etc.
  -- strength (all).
AGC tends to reduce the difference in signal strength, and so removed 
valuable information.


  In situations where static crashes interfere with reception, AGC hang 
time on a loud static crash also increases the length of time that a 
specific static crash interferes with reception.


  I used headphones with good audio isolation between my ears and the 
rest of the world around me.  That allows me to set receiver gain levels 
with the underlying antenna/band noise just above my threshold of 
hearing... and to use at least 80 dB of my hearing range for listening.  
In this quiet listening environment, I don't need AGC.


  Even in a less-than-quiet listening environment, if a band is just 
open weakly (e.g., 12m to Europe), the range of signal strengths in the 
pileup can be smaller: maybe less than 30 dB between band noise and the 
strongest signal.  So AGC isn't needed here either.


  My ideal AGC in these situations is one that only makes changes in 
receiver gain when a stage in the receiver is about to be over-driven 
(e.g., the A/D converter)... and removes those changes relatively 
quickly.  Even then, it might be fine to allow the receiver to be 
over-driven (a static crash contains no information).  If a signal I 
want to copy is over-driving the receiver, the best solution often is to 
reduce the RF gain manually during the duration of the time when I want 
to copy that station.  If that station is just "interference" (e.g., a 
loud USA station on 80m CW calling VP6DX, when I want to work northern 
Scandinavia and northwest Russia/western Asia during the brief opening), 
I have other controls (filter bandwidth, notch) than might be better to 
use that gain reduction (automatic or manual) that could suppress the 
desired weak signals.


  So, almost any AGC system is inappropriate for a DXpedition or 
content environment... as long as the receiver and one's own ears have 
enough dynamic range to handle all the signals presented to it.  The K3 
has more dynamic range than other receivers.


73,
  -- Eric K3NA

on 08 Mar 13 Thu 02:26 Igor Sokolov said the following:

  Almost all of the operators ran the K3 with AGC off (all modes).

-- Eric


Eric, can you explain what did you not like about AGC in K3?
Did you notice any problems with DSP being permanently on in K3 when 
listening to heavy pile ups?


73, Igor UA9CDC


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Re: [Elecraft] VP6DX -- the true story ?

[Eric Scace K3NA]

  Some reported hiccups with the radios should be put into perspective:

1.  We ran 8 radios x 24 hours x 16+ days of operating: over 3,000 hours 
on the air in total... plus additional hours for some units on board ship.


2.  Some glitches were unique a specific radio, or at most two radios.  
As an example, late in the operation one radio seemed to show a T/R 
relay problem where the receiver signals were down temporarily (or 
longer) after a transmission.  Another radio didn't want to power off -- 
it would immediately come back to life after shutdown.
  The "high noise level" was another singleton issue.  One radio, only 
on 30m, and only while in FSK mode, and only when operating split, would 
have its receiver go into oscillation at the end of a FSK transmission.  
If any one of those three conditions did not exist, the radio worked 
fine.  Obviously we moved that radio away from the position with the 30m 
4-square antenna control.  We didn't see that particular quirk on any 
other radio.


3.  We were operating in a demanding field environment: hot temperatures 
in the tents during the day, salty and dusty breezes almost non-stop, 
and perhaps some voltage burbles when the generators ran out of fuel 
unexpectedly.
  On the later point, we did have sealed batteries floated across the 
supply lines, which allowed us to continue operating (without the 1.5 kW 
amplifiers) when generator re-fueling or oil changes were made.  Those 
certainly helped smooth out any power supply variations.


4.  Some items were equipment interaction issues.  For example, our CW 
keying (external to the K3) sometimes hung.  We learned this was due to 
RFI entering the laptop USB port via the external mouse cable, and 
irritating the USB device driver for the microKeyer and/or the microKeyer.


  Almost all of the operators ran the K3 with AGC off (all modes).

-- Eric



on 08 Mar 10 Mon 09:50 Mario Lorenz said the following:

Hi,

besides the "official" report as quoted on the web,
on the BCC mailing list, reports from members of the VP6DX
expedition were slightly less stellar.

While confirming superior receiver sensitivity, problems reported
were with pileup CW reception & AGC,  in T/R switching, 
and internal noise of S9+20 that went away after powercycling

the K3 ???

Since I've just ordered my K3, I'd like to hear whether this has
been confirmed, and hopefully fixed...

Mario

  

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[Elecraft] VP6DX K3 Configuration(s)

[Eric Scace K3NA]

Hi --

  The VP6DX Elecraft K3s were configured as follows:
• KPA3 100W option.
• KXV3 second receive antenna option.
• 2×KFL3A-250 250 Hz 8-pole roofing filter
• 2×KFL3A-400 400 Hz, 8-pole roofing filter
• 2×KFL3A-1.0K 1 kHz, 8-pole roofing filter
• 2×KFL3A-1.8K 1.8 kHz, 8-pole roofing filter
• 2×KFL3A-2.8K 2.8 kHz, 8-pole roofing filter

  We had plans for the 2nd receiver module, but that remains for next 
time...


73,
  -- Eric K3NA
  VP6DX project co-leader

on 08 Mar 01 Sat 09:13 W0JFR said the following:

Could someone post the configurations of the K3's used by the VP5DX Ducie
Island expedition? I would really like to know which roofing filters they
used.  -- 73, W0JFR
  


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Re: [Elecraft] OT: VP6DX es LOTW

[Eric Scace K3NA]

Yes, LOTW will be uploaded for QSLs with donations received in the 
mail.  But this will take longer.  DL6LAU got home to find several 
thousand envelopes in the basement...


Please use the on-line form to request the QSL.  Donations can be sent 
by mail, if desired, but a great deal of time can be saved if you enter 
your QSL request electronically.  Otherwise, someone else (a volunteer) 
will have to do the data entry using the information off your card.


on 08 Mar 07 Fri 10:58 ORIN G. HELVEY,JR. said the following:

Hi Eric,
Thanks for a really great DXpidition! You guys did an awsome job!
Will there be any effort to load to LOTW those of us who are "old
fashioned", and sent a QSL with donation (greater than $5) via mail? Just
wondering.

Thanks,
Orin   N5ORT
K3 On order



On Fri, 07 Mar 2008 00:54:18 -0500 Eric Scace K3NA <[EMAIL PROTECTED]>
writes:
  

Hi Allan --

   We do not send a LOTW entry unless a station asks for a QSL, 
using 
the on-line QSL request form.  In other words, the entire VP6DX log 
is 
not being dumped into LOTW.


   In recognition of the financial help provided by donors, LOTW 
entries 
are being uploaded now for those who have requested QSLs and have 
made a 
donation toward the costs of the DXpedition.


   Some time much later (9-12 months) LOTW entries will be submitted 
for 
QSL requests for non-donors.


   And, of course, there will be a certain number of QSOs that were 
mis-logged or didn't actually occur.  Each of those will require 
manual 
research before making a final decision... so that will delay LOTW 
entries for those specific contacts.


73,
   -- Eric K3NA
   VP6DX co-leader




  

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Re: [Elecraft] OT: VP6DX es LOTW

[Eric Scace K3NA]

Hi Allan --

  We do not send a LOTW entry unless a station asks for a QSL, using 
the on-line QSL request form.  In other words, the entire VP6DX log is 
not being dumped into LOTW.


  In recognition of the financial help provided by donors, LOTW entries 
are being uploaded now for those who have requested QSLs and have made a 
donation toward the costs of the DXpedition.


  Some time much later (9-12 months) LOTW entries will be submitted for 
QSL requests for non-donors.


  And, of course, there will be a certain number of QSOs that were 
mis-logged or didn't actually occur.  Each of those will require manual 
research before making a final decision... so that will delay LOTW 
entries for those specific contacts.


73,
  -- Eric K3NA
  VP6DX co-leader

on 08 Feb 29 Fri 00:39 Allan Taylor said the following:

I have been watching the LOTW the past week and NO entries for VP6DX
have showed up
yet. There should be three, all from the ARRL DX test.

No, I haven't submitted a QSl request but apparently I will need to do so.

Awaiting K3 S/N  !!

K7GT

On Thu, Feb 28, 2008 at 6:19 PM, David Wilburn <[EMAIL PROTECTED]> wrote:
  

I saw mention of LOTW entries being uploaded for folks that had
 donated to the cause.  An interesting idea.  I saw the direct QSL
 information, but nothing else about LOTW.  Has anyone gotten the
 impression that they will be uploading logs to LOTW?
 --


 Dave Wilburn
 K4DGW
 K2/100 - S/N 5982
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[Elecraft] Mic for K3

[Eric Scace K3NA]

Hi Geoff --

  We used Heil HC-5 mic elements (the so-called "full range" element, 
not the "DX operation" element).  Mic gain and compression were both set 
at 15.


  A few operators were caught fidgeting with the mic/compression 
settings, but we tried to discourage changes to these settings.


73,
  -- Eric K3NA
  VP6DX co-leader

on 08 Feb 13 Wed 10:22 Geoffrey Downs said the following:
Re VP6DX - they do sound good. Anyone know what mics and settings they 
are using?


73 to all

Geoff
G3UCK


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