Re: [Elecraft] No Receiver Mute with PTT

[Vic K2VCO]

Bud Morin wrote:

> After many months finally found time to set up my K3 with MH2 
> microphone. Got it updated to version 3.11 and operating fine on cw. But 
> SSB is no go. Using earphones it seems OK and had a QSO that way. Upon 
> removing earphones to use the speaker, WOW, blasted out of room with 
> audio squalling when press PTT. Same thing happens with earphones 
> connected and hold mic next to earphones when use PTT; not loud though. 

This is because you have the MONITOR volume turned up. The monitor allows you 
to hear your 
own signal, which is useful with headphones. But you can't use it with the 
speaker, for 
the reason that you have discovered. In SSB mode, push and turn the MON control 
all the 
way down.

This is not specific to the K3; any rig that has a monitor function will have 
the same issue.
-- 
73,
Vic, K2VCO
Fresno CA
http://www.qsl.net/k2vco
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[Elecraft] No Receiver Mute with PTT

[Bud Morin]

Hi K3 Group,

After many months finally found time to set up my K3 with MH2 
microphone. Got it updated to version 3.11 and operating fine on cw. But 
SSB is no go. Using earphones it seems OK and had a QSO that way. Upon 
removing earphones to use the speaker, WOW, blasted out of room with 
audio squalling when press PTT. Same thing happens with earphones 
connected and hold mic next to earphones when use PTT; not loud though. 
Same thing with zero power or in TEST mode. Have tried various changes 
in configuration but no luck. Don't think the following is connected to 
this problem but have noticed that when turn rf gain down to zero the S 
meter moves all the way up to 80 over S 9 and have been told that on the 
air my voice sounds like too much base. If anyone knows the solution to 
the audio feedback, I would appreciate it if they inform me on what to 
do. Perhaps a another FW download is needed or perhaps a go at parameter 
initialization. Sure hope it is not a hardware.

Thanks for any help.

73,
Bud Morin, K9ZT



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[Elecraft] Elecraft CW Net Report for May 17th & 18th, 2009

[Kevin Rock]

Good Evening,
   The sun is still shining and the temperature is high.  Luckily the weather 
will go back to normal soon otherwise we would have fire danger quickly.  
Currently it is drying very fast so another couple days of dry would bring out 
the firewatch signs; it does feel nice though.  Conditions on both nets were 
fairly good.  A little QSB from certain areas but not too deep.  On 40 meters 
there was evidence of a storm but I only got QRN reports from MN and MI.  I 
heard a few loud snaps but not too many.  We actually have a sunspot and it is 
one of the new cycle ones.  Maybe, just maybe there will be more soon.  The 
lists are a little sparse but I expect that is because so many folks are 
travelling this weekend.  Home from Dayton with heavier baggage and much 
lighter wallets!  I know there is one Begali paddle coming back to Oregon; he 
sent me a photo of Bruna holding it for him ;)  

   On to the lists =>

  On 14050.5 kHz at 2300z:
NO8V - John - MI - K3 - 820
K1THP - Dave - CT - K3 - 686
W6ZH - Pete - CA - K3 - 657
N0AR - Scott - MN - K2 - 4866
W0CZ - Ken - ND - K3 - 457 
NE5DL - David - TX - K3 - 435QNI #50!!!

  On 7045 kHz at 0100z:
NO8V - John - MI - K3 - 820
W6ZH - Pete - CA - K3 - 657
N0TA - John - CO - K3 - 994  QNI #85!!!
WF5W - Cal - TX 
N7SP - Phil - OR - K3 - 1826
W0CZ - Ken - ND - K3 - 457** QNI #275 **
N0AR - Scott - MN - K2 - 4866
K6DGW - Fred - CA - K3 - 642
N6IB - Ron - CA - K2 - 6687
K6PJV - Dale - CA - K3 - 1183
N7KRT - Jeff - TX - K2 - 5471

   If there are any errors please send me an email with the corrections.  This 
morning I went out for a walk and sat on a stump in the nearby clearcut.  I 
looked at the surrounding mountains and saw much less snow than there was even 
yesterday.  Just then a large shadow swept over me.  I looked up and found a 
vulture only ten feet above me.  I made sure to move so he would not start 
gnawing on me.  They don't like their food moving on its own accord; they like 
it a little seasoned ;)  He gave me the eye and I politely told him to move 
along, "This is not the food you are looking for."  
   Tomorrow it is back to work outside.  I need to take advantage of the last 
day of dry weather to work on my vehicles.  Without a garage it makes life 
under a truck not so much fun.  I have changed oil when there was 18 inches of 
snow but it is not my preferred environment.  I got started on a new kit last 
night: a TNC so I can try packet for the ARES folks.  Maybe I can be dragged 
kicking and screaming into the 20th century ;)  
   Until next week stay well,
  73,
 Kevin.  KD5ONS  (Net Control Operator 5th Class)

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[Elecraft] OT VK contest

[rfenabled]

Hi

Further info @

http://www.wia.org.au/members/contests/wavks/

Cheers
Gary
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[Elecraft] OT contest VK

[rfenabled]

Hi All 

In VK land we have a HF contest to work ALL Shires to be run on June 6th.

0600 UTC through to 0600 UTC on June 7th

We will be portable at Cardwell (sea side resort town) in North Queensland 
running VK4GHL

How about some contacts with our fellow K3 owners from over the pond?

Equipment to be used will be;

K3 with 400W amp
4 Element tribander on 12M portable tower
40/80M dipole with 400W

We are also displaying the K3 to the Hamfest gathering there for the annual 
event. Expected attendance in excess of 100 local amateurs. Elecraft provided 
us with a banner and data sheets to help with our display etc.

Please let me know off the reflector any call signs of those wanting to try for 
us. We do get good 20M propagation to the US so I am hopeful...:-)

More @www.vkshires.info

73's and good Dx
Gary
VK4WT
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[Elecraft] NAQCC Sprint Wednesday night!

[NAQCC]

NAQCC Sprint Wednesday night!

This coming Wednesday evening will be the monthly NAQCC Sprint for May, 2009.

I will refer you to the proper URL:

http://www.arm-tek.net/~yoel/sprint200905.html

There you will find all the details as to time, frequencies and also a special 
prize.

This month's Special Award goes to the winner of a drawing among the following: 
The one making the highest score in each division and submitting a sprint 
report for the very first time. A further qualification is that you must have 
made at least 5 QSO's.

This is a monthly event that caters to the CW veteran, the CW newcomer, 
straight key and bug fans. All are welcome to participate (this includes QRO); 
but you must use QRP power levels to compete for awards.

Come join us and have a real good time!

73 de Dave VA3RJ
NAQCC #0004

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[Elecraft] K3 Amps

[rfenabled]

Aptosologynow that was a very clever phrase...tickled my funny bone and 
then some...well put

Wonder how long it will take that to become universal on the reflector?...not 
very is my guess...

Gary *Aptosologist* in training
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[Elecraft] K3 KNOBS

[k4...@juno.com]

In reference to the K3 knobs:
On my K3 one of the large AF/SUB split and one small RF/Sql/sub knob split. 
Elecraft quickly sent me a new set for each shaft.  SN 2223.
Evidently a bad batch.
Thanks,
Jerry, K4DZR

Click here to find the perfect banking opportunity!
http://thirdpartyoffers.juno.com/TGL2131/fc/BLSrjnsKoDOMk9ifbjFr6BjCZI78YIauLtRhx5PHzP6Iv3FeqY5ccEbVuwg/
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Re: [Elecraft] K3 Knobs

[Tim]

The only knobs I've had trouble with are the smaller AF and RF/SQL
concentric knobs.  I've had to replace twice and hope the current ones hold
up.  And, I might say, I've been very careful to not over tighten.  I'll bet
this problem is (or has been) overcome in Aptos!

Tim K5OI K3 0430 (plus a few other Elecraft products!)
Ruidoso, NM

Amazing, does anyone know the serial number range that these brittle knobs
> were shipped?
>
> Are we talking about the four identical knobs but not the VFO's?
>
> So far I have had no need to remove or adjust these.
>
> Gary
> Sent via BlackBerry® from Telstra
>
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Re: [Elecraft] K3 Knobs

[Iain MacDonnell - N6ML]

rfenab...@gmail.com wrote:
> (Snip)
> 
> 
> The knobs in the bad batch will crack/split with just a slight 
> tightening of their set screws.  That's what I encountered.  I've 
> installed many equipment knobs over the years and was careful to not 
> over tighten the sets screws per Elecraft's instructions.   
> Never-the-less the old ones cracked.  Elecraft replaced them and so far 
> all is well.
> END quote:
> 
> Amazing, does anyone know the serial number range that these brittle knobs 
> were shipped?
> 
> Are we talking about the four identical knobs but not the VFO's?

No, we're talking about the AF/RF gain knobs. The "four identical"
ones don't have set-screws.

 ~Iain / N6ML



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[Elecraft] K3 Knobs

[rfenabled]

(Snip)


The knobs in the bad batch will crack/split with just a slight 
tightening of their set screws.  That's what I encountered.  I've 
installed many equipment knobs over the years and was careful to not 
over tighten the sets screws per Elecraft's instructions.   
Never-the-less the old ones cracked.  Elecraft replaced them and so far 
all is well.
END quote:

Amazing, does anyone know the serial number range that these brittle knobs were 
shipped?

Are we talking about the four identical knobs but not the VFO's?

So far I have had no need to remove or adjust these.

Gary
Sent via BlackBerry® from Telstra
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[Elecraft] K3 for sale

[Kr01a]

Forgot to mention that it's actually a K3/100-F  100 watt unit.

73, Mac, KR0I  

**A strong credit score is 700 or above.  See Yours in Just 2 
Easy Steps! 
(http://pr.atwola.com/promoclk/100126575x1222585011x1201462751/aol?redir=http://www.freecreditreport.com/pm/default.aspx?sc=668072&hmpgID=115&;
bcd=Maystrongfooter51709NO115)
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[Elecraft] K3 for sale

[Kr01a]

Have a less than month old K3 assembled by Elecraft for sale.
Radio is much more than I need for my use and more complex
than I desire to learn at my age (80).  It includes a MH2 hand
mike and a 400Hz CW filter.  Contact me directly if interested.
Will sell for $1900 plus shipping.  Payment by USPS money 
orders.  No overseas shipment.
 
73, Mac, KR0I
K.C., MO
**A strong credit score is 700 or above.  See Yours in Just 2 
Easy Steps! 
(http://pr.atwola.com/promoclk/100126575x1222585011x1201462751/aol?redir=http://www.freecreditreport.com/pm/default.aspx?sc=668072&hmpgID=115&;
bcd=Maystrongfooter51709NO115)
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[Elecraft] Elecraft SSB Net results (5/17/09)

[Phil and Christina]

We had a nice SSB net today (1800Z) on 14.316 MHz.  The signal levels were
not particularly good. We had 21 participants including net control and ran
for 22 minutes.  The discussions concerned details about the new watt meter
and 2M transverter, as well as conjecture about the panadapter.
Here is a list of the 21 participants:

Station NameQTH Rig S/N

KE4WY   Jim KY  K3  2165
W2ATO   MortNY  K3  1469
K8MBY   PhilOH  K3  609
NA0FLarry   MN  K3  1953
N1RFB   MarkMA  K3  427
K8EAG   Gil MI  K3  99
N6JWJohnCA  K3  936
W0ANM   Chris   MN  K3  509
W0FMTerry   MO  K3  474
W6VYBob CA  K3  1590
K4GCJ   Gerry   NC  K3  1597
AE6IC   FredCA  K3  2241
KA5KKT  DickKY  K3  1030
W9DVM   PhilFL  K3  1605
W6UONormCA  K3  755
KA0NCR/MArnie   IN  K3  185
W8YMO   Harry   OH  K3  166
K4SOMarkVA  K3  2861
W1JGS   Joe MA  K3  2120
K6TFZ   JeffCA  K3  1190
NS7PPhilOR  K3  1826

Thanks to everybody who checked in.  Have a good week.

73,

Phil, NS7P


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Re: [Elecraft] : Resonance

[Stephen W. Kercel]

Guy:

Interesting points.

73,

Steve
AA4AK


Guy Olinger, K2AV wrote:
>> I was always of the impression that the definition of resonance of a
>> half wave radiator is the condition in which the current at the center
>> is a maximum and the current at the ends is at zero.
>
> This would also be true of a 1/4 wave dipole fed in the center, or any 
> dipole less than a 1/2 wave.  The current would be higher in the 
> center of a less than 1/2 wave dipole, than it would be for the same 
> power fed to the center of a 1/2 wave dipole. No one to my knowledge 
> considers a 1/4 wave dipole "resonant".
>
> I'm not aware of any standard reference that does not define as 
> resonant a 1/2 wave dipole having zero reactance at a center feed. The 
> classic Terman's shows overall circuit current at "resonance" as being 
> entirely resistive. {p.46, Electronic and Radio Engineering 4th 
> Edition, F E Terman, McGraw Hill, 1955}
>
> For the dipole this would be the point that the undissipated power 
> from prior excitation returns exactly in phase with incident 
> excitation.  This is your grid dip meter case of maximum accepted 
> power, hence maximum dip, and also where a center feed displays zero 
> reactive current.
>
> Perhaps a better definition of a wire resonant at a given frequency 
> would be *if there exists* a point on the wire where a feed so placed 
> would not exhibit any reactance. This takes in other cases than center 
> fed 1/2 wave dipoles.
>
> 73, Guy.
>
>

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Re: [Elecraft] KPA-800 any news at Dayton?

[westalto]

Larson..so glad to hear from you again, its been such a long time! 

I really thought it unfair that you pulled so much prison time for that 

stock you sold in your underground antenna scheme. 



Anyway. hope to hear more from you. 



73, 

Doug 

W6JD 


- Original Message - 
From: "Steve Ellington"  
To: dj7...@muenchen-mail.de, "Bill Coleman"  
Cc: elecraft@mailman.qth.net 
Sent: Sunday, May 17, 2009 2:00:41 PM GMT -08:00 US/Canada Pacific 
Subject: Re: [Elecraft] KPA-800 any news at Dayton? 

Elecraft is working on a firmware update which will enable the K3's 800w or 
1500w feature. I believe some minor changes to the DC power input will be 
required however, cooling is already adaquate. No external hardware will be 
necessary and the update is free. The firmware update for the panadapter 
activation has been the hold up. It's been a well guarded secret but 
information is leaking about how the K3's current display is capable of 
displaying any portion of a given band once the new FW is installed. The 
current default display will be minimized to one corner of the screen and 
the remaining area will become the scope. One can toggle between display 
modes by programing one of the PF keys and shortly thereafter we can expect 
the multicolor display firmware update. 

Larson E. Rapp 
Dewey Cheatham and Howe LLP. 
RG8U 


- Original Message - 
From:  
To: "Bill Coleman"  
Cc:  
Sent: Sunday, May 17, 2009 2:53 PM 
Subject: Re: [Elecraft] KPA-800 any news at Dayton? 


> Hi Bill, 
> 
>> I haven't seen any indication that they have decided to end the 
>> amplifier projects. The amps likely would have been out but for the 
>> regulation changes as the RoHS changes. 
> 
> Yes I know about the almost finished state before FCC regulations 
> changed and RoHS was introduced. And if this had not happened, they 
> may well have seen the light of day. To this we can agree. 
> 
> However based on the last two years of K3 craziness, the panadapter 
> development work and so on, as well as my reading between the lines 
> (Aptosology is a bit like Kremlinology back in the 70s) of public and 
> private mails, I get the gut feeling that the KPA800 & KPA1500 amps in 
> their *current* state won't come to market. I would not be surprised 
> if Elecraft in the medium to distant future has reworked/redesigned 
> QRO amplifiers in their product range. 
> 
> I suppose your guess is as good or as bad as mine. 
> 
> vy 73 de toby 
> 
> 
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[Elecraft] Power on 2M

[James Duffey]

I rove in VHF Contests. One key to success in VHF contests in general  
and roving in particular is to be loud on 2M. For other than the QRP  
Portable category, 10 W won't cut it. You will need more power. An  
external amp can be used with the K3's two meter module, but that is  
another thing to hook up in the rover and have go wrong. I hope that  
they will bring out additional VHF modules for the K3 though; a 222  
MHz one would sell very well. - Duffey
--
KK6MC
James Duffey
Cedar Crest NM





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Re: [Elecraft] K3 Knobs

[James Sarte]

The first time I assembled my K3, I took care not to over tighten the
concentric knobs.  However, I had to take them off several times as I had to
troubleshoot a problem I thought I might have been having with the DSP
board.  The last time I reassembled the front panel, in haste and tiredness,
I cranked down the grub screws enough to indent the potentiometer shafts.
As a result, both sets of concentric knobs split in half.  

I called Elecraft the following day and ordered two replacement sets.  I
have since taken care to make sure that the grub screws are only tight
enough to prevent the knob from slipping on its shaft.  One thing I've
noticed though is that the holes drilled in all sets of knobs I received
weren't exactly centered; making alignment and prevention of binding between
knobs a difficult task.  In the end, I had to mix and match knobs until I
found pairs that worked well together without binding.

In the end, the knobs (especially the concentric knobs) are the K3's
cheapest feeling items.  They are poorly manufactured with spotty QC.  I
would rather pay a little extra to have quality machined knobs, or at least
resin knobs with metal ferrules in them.  Of course, whatever Elecraft comes
up with in future, I hope they check to make sure that the holes in the
knobs are perfectly centered.

73 de James K3JPS/2

-Original Message-
From: elecraft-boun...@mailman.qth.net
[mailto:elecraft-boun...@mailman.qth.net] On Behalf Of rfenab...@gmail.com
Sent: Sunday, May 17, 2009 11:25 AM
To: Elecraft
Subject: [Elecraft] K3 Knobs

For the life of me I cannot imagine what is being done to the radio to cause
destruction of the original knobs.

I would not want to be the second owner of those radios as I shudder to
think what the rest of the radio has been subjected to.

Just my initial thought.

My K3 is well over one year old and exhibits no wear and tear, it has been
transported often, used in the field as well as numerous operators and still
looks and works just like it did on day one.

Gary
Sent via BlackBerryR from Telstra
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Re: [Elecraft] KPA-800 any news at Dayton?

[Steve Ellington]

Elecraft is working on a firmware update which will enable the K3's 800w or 
1500w feature. I believe some minor changes to the DC power input will be 
required however, cooling is already adaquate. No external hardware will be 
necessary and the update is free. The firmware update for the panadapter 
activation has been the hold up. It's been a well guarded secret but 
information is leaking about how the K3's current display is capable of 
displaying any portion of a given band once the new FW is installed. The 
current default display will be minimized to one corner of the screen and 
the remaining area will become the scope. One can toggle between display 
modes by programing one of the PF keys and shortly thereafter we can expect 
the multicolor display firmware update.

Larson E. Rapp
Dewey Cheatham and Howe LLP.
RG8U


- Original Message - 
From: 
To: "Bill Coleman" 
Cc: 
Sent: Sunday, May 17, 2009 2:53 PM
Subject: Re: [Elecraft] KPA-800 any news at Dayton?


> Hi Bill,
>
>> I haven't seen any indication that they have decided to end the
>> amplifier projects. The amps likely would have been out but for the
>> regulation changes as the RoHS changes.
>
> Yes I know about the almost finished state before FCC regulations
> changed and RoHS was introduced. And if this had not happened, they
> may well have seen the light of day. To this we can agree.
>
> However based on the last two years of K3 craziness, the panadapter
> development work and so on, as well as my reading between the lines
> (Aptosology is a bit like Kremlinology back in the 70s) of public and
> private mails, I get the gut feeling that the KPA800 & KPA1500 amps in
> their *current* state won't come to market. I would not be surprised
> if Elecraft in the medium to distant future has reworked/redesigned
> QRO amplifiers in their product range.
>
> I suppose your guess is as good or as bad as mine.
>
> vy 73 de toby
>
>
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Re: [Elecraft] : Resonance

[Guy Olinger, K2AV]

> I was always of the impression that the definition of resonance of a
> half wave radiator is the condition in which the current at the center
> is a maximum and the current at the ends is at zero.

This would also be true of a 1/4 wave dipole fed in the center, or any 
dipole less than a 1/2 wave.  The current would be higher in the center of a 
less than 1/2 wave dipole, than it would be for the same power fed to the 
center of a 1/2 wave dipole. No one to my knowledge considers a 1/4 wave 
dipole "resonant".

I'm not aware of any standard reference that does not define as resonant a 
1/2 wave dipole having zero reactance at a center feed. The classic Terman's 
shows overall circuit current at "resonance" as being entirely resistive. 
{p.46, Electronic and Radio Engineering 4th Edition, F E Terman, McGraw 
Hill, 1955}

For the dipole this would be the point that the undissipated power from 
prior excitation returns exactly in phase with incident excitation.  This is 
your grid dip meter case of maximum accepted power, hence maximum dip, and 
also where a center feed displays zero reactive current.

Perhaps a better definition of a wire resonant at a given frequency would be 
*if there exists* a point on the wire where a feed so placed would not 
exhibit any reactance. This takes in other cases than center fed 1/2 wave 
dipoles.

73, Guy. 


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Re: [Elecraft] K3 Knobs

[Stephen Prior]

On 17/05/2009 17:18, "Phil Duff & Ann Duff"  wrote:

> 
> rfenab...@gmail.com wrote:
>> For the life of me I cannot imagine what is being done to the radio to cause
>> destruction of the original knobs.
> No abuse needed and not likely.
> 
> I recently assembled K3/100 #2871 and also had to replace some of the AF
> and RF gain knobs.
> 
> The knobs in the bad batch will crack/split with just a slight
> tightening of their set screws.  Thats what I encountered.  I've
> installed many equipment knobs over the years and was careful to not
> over tighten the sets screws per Elecraft's instructions.
> Never-the-less the old ones cracked.  Elecraft replaced them and so far
> all is well.
> 
> 73 Phil NA4M

You are absolutely right Phil.  I'm not 'ham-fisted' by any means, but both
of the knobs on my K3 (#980) spilt a few months back.  Elecraft sent me a
couple of replacements and I was _even_ more cautious in tightening them up.
One of them started to split within a couple of weeks and I immediately
opened up the splits and filled with epoxy and so far all is still okay, and
you can't see where I glued it.  The other one, tightened to the same degree
of torque is still in one piece.

I note that there is no metal ferrule in these knobs.  Just about every
other knob I have ever fitted has had a (usually) brass ferrule which
happily copes with the stress of a fastening.  I had rather hoped that the
replacement ones supplied to me would have had a metal ferrule too, but they
did not.

73 Stephen G4SJP 

  



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Re: [Elecraft] K3 COOLING VENTS

[Ron D'Eau Claire]

Guy, K2AV, wrote:

Blown solid state finals in HF rigs have been a common complaint in said 
decades-long gossip stream.  

-

It would help if we could see their plates glowing red before they failed. 

Many times I've set the loading on my homebrew rig finals using the color of
the plates to decide max power for the duty cycle being used, and I don't
recall *ever* having to replace a final tube.

Unfortunately, that doesn't work for solid state. 

Modern rigs are like cars with power steering: you crank the knob and hope
the designers did their job so well you don't have to make any judgment
calls. 

That's been true of my K2 for the past decade. 

The few times they discovered something that could go wrong as more
customers like me used (and sometimes abused) the rig, they fixed it with a
mod post haste. 

I expect the same will be true of the K3 over the next decade.   

Ron AC7AC


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[Elecraft] K2 wanted

[Mike Short]

Anyone have one for sale?
 
Mike
 

 

Mike Short

AI4NS

ai...@arrl.net 

 
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Re: [Elecraft] K3 COOLING VENTS

[Guy Olinger, K2AV]

I believe you make my point perfectly. Folks are complaining about displayed 
K3 circuit board and PA heat sink temperatures (not air temp) of 35-45 C as 
if they were somehow dangerous.

While individual components can exceed a measured temp spot in a device, 
good engineering practice in selection of components for their individual 
dissipation in working circuits will insure that the measured spot is 
representative so far as safety is concerned across the circuit.

In the case of a piece of ham gear, anything not so engineered, e.g. a 
poorly designed hot spot, will be destroyed by contesters, and broadly 
complained about, as so well demonstrated over the decades.  Aptos is well 
aware of PVRC and NCCC gossip.  : >)

Blown solid state finals in HF rigs have been a common complaint in said 
decades-long gossip stream.  By height times width times depth volume the 
KPA3 is mostly heat sink and a third of the K3 back panel space is fan mount 
to pull air across said mostly heat sink KPA3. The K3 is a very conservative 
design, heat-wise.

73, Guy

From: "David Woolley (E.L)" 
>> an INTERNAL reading.  If 110 F is a fault temperature, then you could
>> destroy your K3 by leaving it out in the sun.
>
> That's not a valid comparison.  The sort of temperature that will cause
> rapid damage is 150C for silicon semiconductors, something like 100C for
> electrolytics, 75C for the 1N34 germanium point contact diodes, if it
> uses them.  These temperatures are reached when the equipment is
> operating at full power and the insides of the devices are much hotter
> than the point at which the temperature sensor is placed.  If you leave
> the equipment out in the sun, powered down, and the case temperature
> reaches 45C, the inside of the semiconductor devices will also be at
> 45C, well below 150C.  It may be lower, because of thermal inertia.
>
> Typical consumer equipment is designed to tolerate an air temperature of
> 45C whilst keeping the core temperature of internal devices well within
> safety limits.  If you actually operate at that sort of temperature, the
> case temperature and internal temperature will be significantly higher.
>
> Leaving electronics exposed to the sun can, of course, result in
> destroying some of the more temperature sensitive components, as case
> temperatures can get a lot higher than 45C.   Having a large thermal
> mass will help protect the equipment as the sun should start to go down
> before the maximum temperature is reached.


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Re: [Elecraft] [K3] RIT encoder has become flaky

[Frank R. Oppedijk]

I notice this too, although only about once per 20 'ticks'

Frank PA4N


At 21:51 17/05/2009, Bill W5WVO wrote:
>Further clarification: Happens on both RIT and XIT. Not related to a specific
>frequency or band. Happens going in both directions. Sorry I omitted these
>details. All of this points to a hardware problem (shaft encoder), 
>but if anyone
>else has had this issue and fixed it by some other means, please let me know.
>Thanks.

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Re: [Elecraft] [K3] RIT encoder has become flaky

[Bill W5WVO]

Further clarification: Happens on both RIT and XIT. Not related to a specific 
frequency or band. Happens going in both directions. Sorry I omitted these 
details. All of this points to a hardware problem (shaft encoder), but if 
anyone 
else has had this issue and fixed it by some other means, please let me know. 
Thanks.

Bill W5WVO


SidShusterman wrote:
> Bill, which model radio do you have? Does the XIT behave the same
> way? I know the RIT/XIT should be the same for all bands. Does it
> happen both + and - ? Does it happen at 0.85, 1.85 an 2.85?  This
> might make it easier to diagnose. I have had my K3 since January of
> this year and I don't see this.
> Good Luck,
> Sid
>
> Bill W5WVO wrote:
>> As an example -- while slowly turning the RIT knob, the frequency
>> display will go through: .82
>> .83
>> .84
>> .85
>> .84*
>> .85*
>> .84*
>> .84*
>> .83*
>> .84*
>> .85*
>> .86
>> .87
>> etc.
>>
>> The erroneous readouts are starred.
>>
>> This is repeatable, though not necessarily with the same numbers.
>> This would seem to be an encoder problem. Has anyone else
>> experienced this?  Bill W5WVO
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[Elecraft] [K3] RIT encoder has become flaky

[Bill W5WVO]

As an example -- while slowly turning the RIT knob, the frequency display will 
go through:

.82
.83
.84
.85
.84*
.85*
.84*
.84*
.83*
.84*
.85*
.86
.87
etc.

The erroneous readouts are starred.

This is repeatable, though not necessarily with the same numbers. This would 
seem to be an encoder problem. Has anyone else experienced this?

Bill W5WVO
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[Elecraft] RIT encoder has become flaky

[Bill W5WVO]

As an example -- while slowly turning the RIT knob, the frequency display will 
go through:

.82
.83
.84
.85
.84*
.85*
.84*
.84*
.83*
.84*
.85*
.86
.87
etc.

The erroneous readouts are starred. 

This is repeatable, though not necessarily with the same numbers. This would 
seem to be an encoder problem. Has anyone else experienced this?

Bill W5WVO
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Re: [Elecraft] KPA-800 any news at Dayton?

[dj7mgq]

Hi Bill,

> I haven't seen any indication that they have decided to end the
> amplifier projects. The amps likely would have been out but for the
> regulation changes as the RoHS changes.

Yes I know about the almost finished state before FCC regulations  
changed and RoHS was introduced. And if this had not happened, they  
may well have seen the light of day. To this we can agree.

However based on the last two years of K3 craziness, the panadapter  
development work and so on, as well as my reading between the lines  
(Aptosology is a bit like Kremlinology back in the 70s) of public and  
private mails, I get the gut feeling that the KPA800 & KPA1500 amps in  
their *current* state won't come to market. I would not be surprised  
if Elecraft in the medium to distant future has reworked/redesigned  
QRO amplifiers in their product range.

I suppose your guess is as good or as bad as mine.

vy 73 de toby


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[Elecraft] Simple metal knobs

[Jim Miller KG0KP]

I like mine jsut fine but if you like aluminum - they look nice too -

First page on Google search - I'm sure there are a lot available -

http://www.surplussales.com/ShaftHardware/Knobs-9.html
 3/4 and 15/16 aluminum.  6mm bores - are elecraft 1/4"?  Close and could be 
drilled out on a drill press if they are too tight.

73, de Jim KG0KP

- Original Message - 
From: "Doug Faunt N6TQS +1-510-655-8604" 
To: 
Sent: Sunday, May 17, 2009 1:14 PM
Subject: Re: [Elecraft] KPA-800 any news at Dayton?- and knobs


>   Date: Sun, 17 May 2009 19:41:47 +0200
>   From: dj7...@muenchen-mail.de
>
>   I do understand why Elecraft has (probably) decided to end the QRO
>   amplifier project. It would have been difficult breaking into a small
>   market with an expensive high end product and not loose money. And
>   Elecraft is a fairly small company with relatively large number of
>   products, so overreaching could also harm the stuff they already have,
>   e.g. quality control.
>
> OTOH, the better they do, the more they'll be able to put into new
> products, so buy more Elecraft and that'll mena the amp will be more
> likely to come along soon.
>
> BTW, how many people noted Lyle's mention of the KXV3A allowing
> connections of intenal options, "such as the KXV144"- dare we hope for
> 432 and maybe even full-duplex?
>
> Also, if people want really nice knobs for their K3, they might want
> to consider "3D printing" such as described here:
> http://www.bathsheba.com/sculpt/process/
>
> 73, doug
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> 


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Re: [Elecraft] KPA-800 any news at Dayton?

[Bill Coleman]

On May 17, 2009, at 1:41 PM, dj7...@muenchen-mail.de wrote:

> I do understand why Elecraft has (probably) decided to end the QRO
> amplifier project.


I haven't seen any indication that they have decided to end the  
amplifier projects. The amps likely would have been out but for the  
regulation changes as the RoHS changes.

The biggest obstacle has probably been the overwhelming success of the  
K3. Elecraft had been in a backorder situation on that one product for  
more than a year. The K3 has clearly absorbed all of the creative  
energy of Elecraft for the last couple of years. That may not continue  
forever -- so the amps may see the light of day, as well as other  
projects.

Bill Coleman, AA4LR, PP-ASELMail: aa...@arrl.net
Web: http://boringhamradiopart.blogspot.com
Quote: "Not within a thousand years will man ever fly!"
 -- Wilbur Wright, 1901

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Re: [Elecraft] KPA-800 any news at Dayton?- and knobs

[Doug Faunt N6TQS +1-510-655-8604]

   Date: Sun, 17 May 2009 19:41:47 +0200
   From: dj7...@muenchen-mail.de

   I do understand why Elecraft has (probably) decided to end the QRO  
   amplifier project. It would have been difficult breaking into a small  
   market with an expensive high end product and not loose money. And  
   Elecraft is a fairly small company with relatively large number of  
   products, so overreaching could also harm the stuff they already have,  
   e.g. quality control.

OTOH, the better they do, the more they'll be able to put into new
products, so buy more Elecraft and that'll mena the amp will be more
likely to come along soon.

BTW, how many people noted Lyle's mention of the KXV3A allowing
connections of intenal options, "such as the KXV144"- dare we hope for
432 and maybe even full-duplex?

Also, if people want really nice knobs for their K3, they might want
to consider "3D printing" such as described here:
http://www.bathsheba.com/sculpt/process/

73, doug
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Re: [Elecraft] KPA-800 any news at Dayton?

[dj7mgq]

To tell you the truth I am not surprised, especially because Eric did  
say ahead of Dayton that the amps were not coming any time soon. That  
is not to say that I am not disappointed, because I have been waiting.  
There are other good amps on the market, but the integration with the  
K2/K3 sounded like it was going to be very advanced and the built in  
"tuner" in combination with solid state would have been very nice  
indeed. I'll now have to raid my "amplifier upgrade piggy bank" for  
some other manufacturer.

I do understand why Elecraft has (probably) decided to end the QRO  
amplifier project. It would have been difficult breaking into a small  
market with an expensive high end product and not loose money. And  
Elecraft is a fairly small company with relatively large number of  
products, so overreaching could also harm the stuff they already have,  
e.g. quality control.

vy 73 de toby
-- 
DD5FZ (ex dj7mgq, dg5mgq, dd5fz)
K2 #885, K2/100 #3248. K3/100 #67

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Re: [Elecraft] another K2 building question

[David Woolley (E.L)]

Daniel Kreithen wrote:

> I've reached the point in the K2 build just before the RF board
* assembly, part II, and am performing the recommended tests. Everything
* checks out fine except for one thing: I can't set the AGC threshold to
* the recommended 3.80 volts. Adjusting the potentiometer R1 on the
* control board makes the voltage at pin 5 of U2 top out at 3.64 volts. Is
* this a problem (I imagine it is!). Where do I start looking for an
* issue? Thanks,

Probably the number 1 K2 builder question.  It is generally not a 
problem.  All the components need to be at, or beyond, the centre of 
their tolerance to achieve this figure.  Quite often the 8V regulator, 
is towards the low end of its tolerance.  Measure, it.  If it is low, 
but within tolerance, there is probably no point in doing anything.  If 
it is low and out of tolerance, request a replacement.  If it is high, 
you may have a real problem.
> 


-- 
David Woolley
"The Elecraft list is a forum for the discussion of topics related to 
Elecraft products and more general topics related ham radio"
List Guidelines 
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[Elecraft] : Resonance

[Stephen W. Kercel]

Don:

Regarding the complex impedance of an antenna at the end point, you 
raise some interesting questions.

I was always of the impression that the definition of resonance of a 
half wave radiator is the condition in which the current at the center 
is a maximum and the current at the ends is at zero. The current 
distribution in a half wave antenna is analogous to the displacement of 
a violin string, which when vibrating at resonance has zero displacement 
at the ends and maximum displacement at the center. (Such a resonance is 
easily detected with a grid dip meter, even if no feedline at all is 
connected to the radiator. Admittedly, the feedpoint would need to be 
shorted. Sweeping the grid dip meter through a range of frequencies is 
analogous to the broadband energy in the "pluck" on the violin string. 
In either case (assuming very high Q), only the energy at the resonant 
frequency actually gets coupled into the device.)

In the case of center fed half wave element, a zero value of imaginary 
component of impedance at a center feed point is a coincidental 
indication of antenna resonance rather than the definition of antenna 
resonance; it is used by amateurs because it is easy to measure, whereas 
the current distribution is almost impossible to measure directly.

If you run the "BY dipole" simulation on EZNEC at a frequency and 
radiator length for which the center feedpoint impedance is pure 
resistance, and then move the feedpoint around, the radiation pattern 
comes out just the same (within the limits of computational error) 
regardless of the feedpoint location. Also, the magnitude of the current 
distribution remains about the same, big in the center and approaching 
zero at the ends. Thus, my sense is that by the analogy to the violin 
string, the antenna is resonant at that length for that frequency 
irrespective of the feedpoint location, or the fact that the feedpoint 
impedance is complex.

Admittedly, that much of the discussion is literally academic, depending 
on how we define resonance.

However, you raise another question that is more practical than 
academic. You make the perfectly reasonable point that if I play around 
with the radiator length, I should find a length that has an end 
feedpoint impedance of some big value of R plus J0. I am sure you can do 
that, but my question to you is, what is the advantage to doing so? 
(Note: This is not intended as a smart aleck comment. If there is some 
advantage easily obtained by tweaking the radiator length, I'd really 
like to know what it is.) I do not expect that minimizing radiation from 
the transmission line is one of those advantages. Changing the radiator 
length such that you move away from the length that gives "violin string 
resonance" would make the current distribution on the radiator more 
asymmetrical and would increase the probability of feed line radiation.

This line of reasoning got me curious about something else. Elecraft 
rigs are usually rated as being able to operate normally for any load 
that has an SWR of 2 or less compared to a characteristic impedance of 
50+J0. Am I correct in assuming that that means that the rig expected to 
be able to operate normally into any complex load on or inside the SWR = 
2 circle on the Smith Chart?

Why that matters is the following. Using a high impedance quarter wave 
(approximately) transformer to Zepp feed a half wave radiator, it is 
relatively straightforward to tweak the transformer length such that the 
subsequent 50 Ohm coax has an SWR well inside the SWR = 2 circle. If so, 
the Elecraft rig should be perfectly happy, even if I seldom if ever 
actually find an impedance with a zero imaginary component.

Have I missed something in my thinking? (It would not be the first time.)

TNX & 73,

Steve Kercel
AA4AK










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[Elecraft] another K2 building question

[Daniel Kreithen]

Hi - 

I've reached the point in the K2 build just before the RF board assembly, part 
II, and am performing the recommended tests.  Everything checks out fine except 
for one thing:  I can't set the AGC threshold to the recommended 3.80 volts.  
Adjusting the potentiometer R1 on the control board makes the voltage at pin 5 
of U2 top out at 3.64 volts.  Is this a problem (I imagine it is!).  Where do I 
start looking for an issue?  Thanks,

Dan Kreithen
AE3E
dkreit...@hotmail.com


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Re: [Elecraft] K3 Knobs

[Phil Duff & Ann Duff]

rfenab...@gmail.com wrote:
> For the life of me I cannot imagine what is being done to the radio to cause 
> destruction of the original knobs.
No abuse needed and not likely.

I recently assembled K3/100 #2871 and also had to replace some of the AF 
and RF gain knobs.

The knobs in the bad batch will crack/split with just a slight 
tightening of their set screws.  Thats what I encountered.  I've 
installed many equipment knobs over the years and was careful to not 
over tighten the sets screws per Elecraft's instructions.   
Never-the-less the old ones cracked.  Elecraft replaced them and so far 
all is well.

73 Phil NA4M

-- 
-. .- - --   -. .- - -- -. .- - --
Phil Duff NA4M & Ann Duff
Georgetown, Texas
http://priceless.apduff.com
http://stockphoto.apduff.com

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Re: [Elecraft] K3 Knobs

[Andreas Junge]

No abuse to the radio at all. The material appears to be too brittle.  
Slightly torque  the set screw and the knob will split. Eric already  
said the composition has been changed to fix this, so there was a  
problem.

Andreas, N6NU




On May 17, 2009, at 8:25 AM, rfenab...@gmail.com wrote:

> For the life of me I cannot imagine what is being done to the radio  
> to cause destruction of the original knobs.
>
> I would not want to be the second owner of those radios as I shudder  
> to think what the rest of the radio has been subjected to.
>
> Just my initial thought.
>
> My K3 is well over one year old and exhibits no wear and tear, it  
> has been transported often, used in the field as well as numerous  
> operators and still looks and works just like it did on day one.
>
> Gary
> Sent via BlackBerry® from Telstra
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Re: [Elecraft] K3 144mhz power - 10 watts not a problem

[Erik N Basilier]

Exactly. On 144 the weak signals are so weak that TX cleanness as well as RX 
dynamic range become a very difficult problems. You want a minimum number of 
TX stages to mess up the signal, and minimum phase noise. Most solid state 
amp's that might be available in the shack may not be clean enough to drive 
the big one. Hmmm years ago I was looking at a 144 legal limit amp 
project described in the 1988 ARRL Handbook. It uses a tetrode and produces 
full output with just 10W in. That one is now back on my list of dreams

73,
Erik K7TV

- Original Message - 
From: "Mike Harris" 
To: "Elecraft Reflector" 
Sent: Sunday, May 17, 2009 8:26 AM
Subject: Re: [Elecraft] K3 144mhz power - 10 watts not a problem


> Cascading IPs maybe if you're running an intermediate amp to drive the big
> one.
>
> Regards,
>
> Mike VP8NO
>
> - Original Message - 
> From: "Jim Miller KG0KP" 
> To: "Elecraft Reflector" 
> Sent: Sunday, May 17, 2009 12:33 AM
> Subject: Re: [Elecraft] K3 144mhz power - 10 watts not a problem
>
>
> |I don't see 10 watts as a problem.  How many 2 meter amps do you have on
> the


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Re: [Elecraft] K3 144mhz power - 10 watts not a problem

[Mike Harris]

Cascading IPs maybe if you're running an intermediate amp to drive the big 
one.

Regards,

Mike VP8NO

- Original Message - 
From: "Jim Miller KG0KP" 
To: "Elecraft Reflector" 
Sent: Sunday, May 17, 2009 12:33 AM
Subject: Re: [Elecraft] K3 144mhz power - 10 watts not a problem


|I don't see 10 watts as a problem.  How many 2 meter amps do you have on 
the
| shelf just waiting to be used again?  40 w 15 years old ($90 new then), 
two
| converted police amps (ugly but they work well) both run over 85 watts
| continuous with 5 watts in ($50) at hamfests if there any still around) 
and
| a 140 w that takes 2 watts drive for full power and the other is a 160 w
| that runs full output at 35 watts and over half of that from an ht 
(don't
| remember exactly how much).  10 watts a problem? - i just don't see it.
|
| Lots of external amps out there.
| 73, Jim KG0KP

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[Elecraft] K3 Knobs

[rfenabled]

For the life of me I cannot imagine what is being done to the radio to cause 
destruction of the original knobs.

I would not want to be the second owner of those radios as I shudder to think 
what the rest of the radio has been subjected to.

Just my initial thought.

My K3 is well over one year old and exhibits no wear and tear, it has been 
transported often, used in the field as well as numerous operators and still 
looks and works just like it did on day one.

Gary
Sent via BlackBerry® from Telstra
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[Elecraft] is anyone opperating the k2 at 750hz sidetone?

[dw]

Hey Gang,
Is anyone operating your k2 with a 750Hz sidetone?
If so, what do you have as your BF1,BF2,BF3,BF4 setting values?
And how do you get the unit to save new values!!!

I'm thinking my unit has a problem as it seems to be refusing to accept
BFO changes.

For example right now BF4 is set to 075c
I want to change it to 072c
I adjust it to 072c and then per the manual I press MENU, or XFIL or
AGC.
It doesn't matter what I press, the unit will go right back to the BF4
075c setting. 

I'm either stupid or the rig has a problem!!
-- 
 bw...@fastmail.net

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Re: [Elecraft] Tr: K3 Ref connector

[Wes Stewart]

--- On Sun, 5/17/09, Brendan Minish  wrote:

> From: Brendan Minish 
> Subject: Re: [Elecraft] Tr: K3 Ref connector
> To: "David Pratt" 
> Cc: elecraft@mailman.qth.net, "Dave G4AON" 
> Date: Sunday, May 17, 2009, 6:44 AM
> On Sat, 2009-05-16 at 08:03 +0100,
> David Pratt wrote:
> > The connector is referred to on page 17 of the latest
> K3 Owner's Manual 
> > and my K3 rear panel is labelled "REF."
> > 
> > In consequence, I have bought a Racal-Dana 9474
> Rubidium Frequency 
> > Standard which is now poised to plug in as soon as the
> KREF3-EXT is 
> > available, hopefully quite soon.
> 
> Couple of thoughts here 
> 
> Unlike the Racal RA3702 I have here; the K3 is incapable of
> phase
> accuracy (RF to audio), or indeed exact frequency accuracy
> (multiple DDS
> LO conversions with ensuing decimation errors, varying
> offsets for
> roofing filter positioning etc)     

Correct. I have been able to hear, or more easily see using Spectrum Lab, the 
change in pitch on a signal while simply changing the DSP bandwidth.

There is a lot of frequency changing going on when the passband is moved and 
not every oscillator moves at the same rate.

Best have another receiver around for the FMT.

Wes  N7WS


  
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Re: [Elecraft] Broken K3 Knobs

[James Sarte]

I know this is just wishful thinking, but it would be nice to have machined
aluminum knobs instead of plastic or resin.  

James K3JPS/2

-Original Message-
From: elecraft-boun...@mailman.qth.net
[mailto:elecraft-boun...@mailman.qth.net] On Behalf Of W0FK
Sent: Saturday, May 16, 2009 10:56 PM
To: elecraft@mailman.qth.net
Subject: Re: [Elecraft] Broken K3 Knobs


About 1000 of the knobs were maufactured improperly, which has since been
corrected. Eric told me at Dayton that future knobs will have a glass
additive in them so that they will be virtually indestructible.

Email parts at Elecraft and they will promptly send replacements.  

73,

Lou, W0FK



Duker wrote:
> 
> Just received (5/5/09) my K3, serial #02969 and both the AF and RF gain
> knobs were cracked.  After few turns of the knobs (spin on the control
> shaft) they no longer would increase or decrease levels. Called
> Elecraft...immediately said new control knobs would be in the mail. As
> other have commented the knobs appear flemsy and very light duty.
> Hopefully Elecraft will take corrective action.   Anyone find a suitable
> replacement? Thanks for your comments...K2HDU...Ken
> 


-
St. Louis, MO
K3 #2513
-- 
View this message in context:
http://n2.nabble.com/Broken-K3-Knobs-tp2913132p2914832.html
Sent from the Elecraft mailing list archive at Nabble.com.

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Re: [Elecraft] Tr: K3 Ref connector

[Paul Christensen]

> As a result phase locking or replacing the internal REF with a highly
> stable and accurate external source is not likely to be very useful.

Brendan raises an interesting point.  I use an HP 58540A GPS/DO with an 
IC-7800 and note some of the same decimation errors that he addresses --  
although my long term accuracy is much better than +/- 0.25 Hz, but 
certainly not anywhere near the accuracy offered by the GPS/DO for the 
reasons that Brendan stated.  That said, anyone know the maximum accuracy 
deviation owing to decimation error when using the K3's architecture?

Although my K3 has the high-stability TCXO option, the long-term accuracy of 
the IC-7800 with HP 58540A is still significantly better.  Note that I'm 
discussing the long-term stability.  To some extent, Elecraft's forthcoming 
TCXO calibration algorithm may better match the characteristics of the TCXO 
and offer better long-term stability over that which I'm now measuring.

The importance of this is pretty much relegated to a footnote.  Not many of 
us need the extreme levels of accuracy we're discussing, but it's an 
interesting exercise to extract the highest degree of frequency accuracy 
possible from any transceiver.

Paul, W9AC


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Re: [Elecraft] Tr: K3 Ref connector

[Brendan Minish]

On Sat, 2009-05-16 at 08:03 +0100, David Pratt wrote:
> The connector is referred to on page 17 of the latest K3 Owner's Manual 
> and my K3 rear panel is labelled "REF."
> 
> In consequence, I have bought a Racal-Dana 9474 Rubidium Frequency 
> Standard which is now poised to plug in as soon as the KREF3-EXT is 
> available, hopefully quite soon.

Couple of thoughts here 

Unlike the Racal RA3702 I have here; the K3 is incapable of phase
accuracy (RF to audio), or indeed exact frequency accuracy (multiple DDS
LO conversions with ensuing decimation errors, varying offsets for
roofing filter positioning etc) 

As a result phase locking or replacing the internal REF with a highly
stable and accurate external source is not likely to be very useful. The
(better than) 1ppm ref carefully set up and used in a stable temperature
environment is probably approaching the limits of the K3's architecture
with regard to frequency setting accuracy. (although an external ref may
further improve frequency stability. ) 

The K3 is not alone here, my Icom IC-7800 was often up to 0.25 Hz or so
off frequency when driven with a external GPS disciplined Rubidium
reference source, I suspect that the main cause of this was DDS
Decimation errors but it was also an issue between main and sub making
true diversity a non-runner on the 7800 despite having so called
'matching' main and sub receivers. 

Lastly be careful with Rubidium as it's phase noise performance is far
poorer than a good Xtal Reference and this can be a problem at times as
it may degrade the strong signal performance of a High Dynamic range
receiver. 

I am a time nut and do make on occasion some interesting measurement on
LF & HF with my RA3702 using my external 10MHz ref but I do not think I
will be adding this external locking feature to the K3 when it is
released.

-- 
73
Brendan EI6IZ 

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Re: [Elecraft] Reminder - UK Elecraft net Sundays 0900 local 3630 KHz

[AD6XY]

Dave G4AON wrote:
> 
> The frequency is 3630 KHz plus or minus the QRM.
> The new start time is 0900 hours local (0800 UTC) in an effort
> to try and beat the deteriorating summer band conditions.
> 
> 73 Dave, G4AON
> K3/100, Acom 1000, dipole
> 
> 
> 
> 
> 
> Sorry - I can't make it as I am at Dayton and 4am is a little early for
> me. Nice new Elecraft stuff here though.
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
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> 
> 

-- 
View this message in context: 
http://n2.nabble.com/Reminder---UK-Elecraft-net-Sundays-0900-local-%3Cnew-start-time%3E-3630-KHz-tp2912949p2915941.html
Sent from the Elecraft mailing list archive at Nabble.com.

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Re: [Elecraft] UK Elecraft net report for Sunday 17th May

[Peter Connors]

The earlier start made your 400w 52 in south west France but the rest of 
the net was among or below the noise. Perhaps in the autumn...

Pete F5VNB

Dave G4AON wrote:
> Conditions were OK for most of us this week.
> 
> The net ran on 3631 KHz from 0900 to 0953 hours local (0800 -
> 0853 UTC).
> 
> There was some interest in the recently announced W2 power meter
> and K144XV 2m K3 internal transverter. We had a discussion on
> the level of AM modulation from the K3, mine gives 85% mod on a
> whistle and seems well modulated to me. Running AM with the K3
> and Acom 1000 gives a nice 100 Watt carrier (400W PEP) which is
> the UK limit for AM.
> 
> Stations were:
> 
> G3YPZ, John
> G3XGC, Geoff
> G0VGS, Ian
> M3WCK, Colin
> G4CGG, Richard
> 
> 73 until next week
> Dave, G4AON
> K3/100, Acom 1000, dipole
> 
> 
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> 
> 


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[Elecraft] UK Elecraft net report for Sunday 17th May

[Dave G4AON]

Conditions were OK for most of us this week.

The net ran on 3631 KHz from 0900 to 0953 hours local (0800 -
0853 UTC).

There was some interest in the recently announced W2 power meter
and K144XV 2m K3 internal transverter. We had a discussion on
the level of AM modulation from the K3, mine gives 85% mod on a
whistle and seems well modulated to me. Running AM with the K3
and Acom 1000 gives a nice 100 Watt carrier (400W PEP) which is
the UK limit for AM.

Stations were:

G3YPZ, John
G3XGC, Geoff
G0VGS, Ian
M3WCK, Colin
G4CGG, Richard

73 until next week
Dave, G4AON
K3/100, Acom 1000, dipole


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Re: [Elecraft] K3 COOLING VENTS

[David Woolley (E.L)]

Guy Olinger, K2AV wrote:

> an INTERNAL reading.  If 110 F is a fault temperature, then you could
> destroy your K3 by leaving it out in the sun.

That's not a valid comparison.  The sort of temperature that will cause 
rapid damage is 150C for silicon semiconductors, something like 100C for 
electrolytics, 75C for the 1N34 germanium point contact diodes, if it 
uses them.  These temperatures are reached when the equipment is 
operating at full power and the insides of the devices are much hotter 
than the point at which the temperature sensor is placed.  If you leave 
the equipment out in the sun, powered down, and the case temperature 
reaches 45C, the inside of the semiconductor devices will also be at 
45C, well below 150C.  It may be lower, because of thermal inertia.

Typical consumer equipment is designed to tolerate an air temperature of 
45C whilst keeping the core temperature of internal devices well within 
safety limits.  If you actually operate at that sort of temperature, the 
case temperature and internal temperature will be significantly higher.

Leaving electronics exposed to the sun can, of course, result in 
destroying some of the more temperature sensitive components, as case 
temperatures can get a lot higher than 45C.   Having a large thermal 
mass will help protect the equipment as the sun should start to go down 
before the maximum temperature is reached.


-- 
David Woolley
"The Elecraft list is a forum for the discussion of topics related to 
Elecraft products and more general topics related ham radio"
List Guidelines 
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Re: [Elecraft] OT - SteppIR Vertical and Elecraft Products

[David Cutter]

Have a look at QEX this month.  W6WO shows an excellent method I have not 
seen before.  He feeds 10% in from the end and uses a simple 4:1 
transformer.  His capacitor is just a compression trimmer.  It is coax fed 
via a choke and runs to 100W.

Also look at AA5TB website for end feds.  Kite flyers use them a lot.

The attraction for me is that I can have a single lightweight wire supported 
by a flimsy fishing pole and the heavy coax is near the transmitter at 
near-ground level.  The 10% tail end does not need to be in-line, it can be 
bent out of the way for safety and tidiness.  I've modelled several 
configurations and they are mostly good for NVIS unless vertical.  I 
modelled 30ft horizontal at 4ft above ground then 34ft vertical (up the 
fibreglass pole) and that gives a small f/b of 6dB and useful low angle take 
off.  Great for mini-dxpeditions and back-packers, especially good next to 
the sea of course.

David
G3UNA

- Original Message - 
From: "Stephen W. Kercel" 
To: 
Cc: "'Elecraft Discussion List'" 
Sent: Sunday, May 17, 2009 3:37 AM
Subject: Re: [Elecraft] OT - SteppIR Vertical and Elecraft Products


> Willis and others:
>
> There is a much cheaper trick than big coils and capacitors that ought
> to work, and could easily handle high power.
>
> Although I have never tried end feeding a half wave antenna, I have had
> great success in center feeding full wave antennas. The trick is to use
> an open wire feedline as a quarter wave transformer. I used the old
> fashioned "ladder line" with plastic spreaders and bare copper wire
> rated at 450 Ohms. Since the velocity factor is practically 1, I cut the
> length to the theoretical free space quarter wavelength. One end feeds
> the center of the antenna, and the other end goes to a 1:1 balun. It
> presents a very low SWR to 50 Ohm coax. I have done this on various
> bands with great success.
>
> I have not tried the "end fed Zepp" configuration implied by an end
> feeding scheme, but for the sake of this discussion, I have run a quick
> simulation.
>
> Here's what the math says:
>
>
> I ran the "Backyard Dipole" File that Roy provides with  with EZNEC. I
> Moved the feedpoint to one end, changed the ground conditions to
> "Real-Medium" and included the copper losses in the wire.
>
> The computed end point impedance at 14 MHz (where it is a half
> wavelength) 1282-J1791.
>
> If you use 450 Ohm window ladder line in the TLW program and use a 14
> foot length of line in the traditional single ended Zepp fed
> configuration, the impedance at the input of the transmission line is
> 43.15-J18.06. Connecting RG-8 to that works out to an SWR of about 1.5
> on the coax.
>
> In the simulation the transformer length did not turn out to be exactly
> a quarter wavelength. I had to tweak it a bit to find a workable
> transformation. In practice, the ground losses will not be exactly the
> same as the simulation, and one might have to play a bit  with the
> transformer length when you try it for real.
>
> However, my experience with the "double Zepp" scheme above is that it is
> not that hard to find the right line length and the antenna is quite
> forgiving in practice. I see no reason why a single ended Zepp scheme
> should be significantly more difficult to do in practice.
>
> Some posters may object that the antenna's behavior is impractical to
> predict because  the end point impedance can vary over a wide range.
> That is true, but by using a quarter wave transformer with relatively
> high characteristic impedance, that wide range at the high-Z end is
> transformed to a narrow range at the low-Z end.  Thus, in practice, with
> perhaps a bit of tweaking, using this scheme will give you acceptable
> SWR in the coax, even if your actual impedance numbers are not the same
> as my numbers.
>
> 73,
>
> Steve Kercel
> AA4AK
>
> 
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