Contesting - Recent changes [en]

K3NA notebook: W1KM work queue

Eric Scace — Sun, 06 Dec 2009 04:18:12 GMT

New page

[[Category:K3NA notebook:W1KM]]
<div style="background-color:#E0FFFF">
Lead person in '''bold'''.
==Repairs==
''Prioritized by severity of performance impact.''
# 80m 4-square: NW element down; guy anchor must be replaced. '''W1KM''' Scheduled 2009 Dec 08 Tue if weather OK.
# 20m mult rotator control box: Send to Alfa-Spid for repair to pulse detector. Alfa-Spid sending loaner unit 2009 Dec 03. '''K3NA'''
# Position E: microKeyer (either MK or MK-II) occasionally hangs with PTT=on at end of a transmission. Requires power to be cycled to restore operation. Could be RF getting into the unit. Try earthing and add ferrite to signal/power cables. Noted in 2009 ARRL DX, WW ph and WW cw.
# Overhead cabinet above fridge appears to be coming off its mount; it is resting on the flourescent light fixture below. Rehang. '''Ask K1EO?'''
# SGC +13 Vdc supply: Repair voltage regulator. K3NA to deliver to K1XM at next YCCC meeting. '''K1XM'''
# Exterior floodlight motion detector failing. Replace.

==Clean-up==
* Computers & network:
** Add N1MM function labels to keyboards. Requires some thought about N1MM keypresses, AutoHotKey assignment changes for the Mac keyboards.
* K3 installation:
** Verify voice from computer is routed to K3 rear panel mic, and K3 is looking for rear panel mic input on SSB.
** Document microKeyer USB router configuration for MK2R+, MK-II. '''K3NA'''
* Operating desk:
** Research copper surface installation procedures. Get quote for materials. Decide whether to finish with copper or laminate. Remove equipment, install surface, and re-install equipment. '''K3NA + K1EO'''
* Window: Finish spackling; sand; paint. Install second window. '''W1KM'''

==Pre-contest checklist:==
* Computers & network:
** N1MM Logger brought to current release.
** Create directory in My Computer/Shared Documents/Logs for the contest with name ''yyyy mm [contest name] [mode] [call used]''. Example: My Computer/Shared Documents/Logs/2009 10 WW ph K3NA. All N1MM Logger files and audio archives will be placed here.
** wl_cty file brought to current release. Archive copy placed in ''Shared Docs/Logs/[contest]'' directory.
''(to be continued)''

==Post-contest checklist:==

==Routine maintenance==
* Computers & network:
**

==New development==
</div>

K3NA notebook: W1KM: Contests

Eric Scace — Sat, 05 Dec 2009 18:58:37 GMT

New page

[[Category:K3NA notebook:W1KM]]
<div style="background-color:#E0FFFF">

{| border="1" style="text-align: left; background-color:#E0FFFF;"
|+ '''Contests and results from the W1KM site'''
|-
! contest
! date
! call used
! ops
! category
! result
|-
| ARRL 160m || 2009 Dec || W1UE || W1UE || SOHP ||
|-
| WW CW || 2009 Nov || W1KM || K3NA KT1D W1KM || MM ||
160: 197 17 68
80: 938 24 106
40: 1425 35 138
20: 1760 36 136
15: 785 29 120
10: 41 10 22
tot: 5146 151 590
10,876,398 (preliminary)
|-
| WW ph || 2009 Oct || K3NA || K1EO K1VR K3NA KT1D W1FJ W1KM || MM ||
160: 162 16 61
80: 515 21 90
40: 866 31 120
20: 1243 34 135
15: 996 30 128
10: 141 9 28
tot: 3923 141 562
7,768,853 (preliminary)
|-
|}
</div>

K3NA:W1KM

Eric Scace — Sat, 05 Dec 2009 13:59:03 GMT

moved [[K3NA:W1KM]] to [[K3NA notebook:W1KM]]

New page

Category:K3NA:W1KM

Eric Scace — Sat, 05 Dec 2009 13:58:34 GMT

← Older revision		Revision as of 13:58, 5 December 2009
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	#REDIRECT [[K3NA notebook:W1KM]]		#REDIRECT [[K3NA notebook:W1KM]]
-	~~[[Category:K3NA notebook]]~~

Category:K3NA notebook:W1KM

Eric Scace — Sat, 05 Dec 2009 13:57:51 GMT

Redirected page to K3NA notebook:W1KM

New page

#REDIRECT [[K3NA notebook:W1KM]]
[[Category:K3NA notebook]]

K3NA notebook: W1KM antennas

Eric Scace — Sat, 05 Dec 2009 13:57:00 GMT

← Older revision		Revision as of 13:57, 5 December 2009
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-	[[Category:K3NA:W1KM]]	+	[[Category:K3NA notebook:W1KM]]
	<div style="background-color:#E0FFFF">		<div style="background-color:#E0FFFF">
	''Note:'' A placeholder where we are starting to accumulate information. [[User:Eric Scace\|Eric K3NA]] 13:53, 5 December 2009 (UTC)		''Note:'' A placeholder where we are starting to accumulate information. [[User:Eric Scace\|Eric K3NA]] 13:53, 5 December 2009 (UTC)

Category:K3NA:W1KM

Eric Scace — Sat, 05 Dec 2009 13:55:53 GMT

Redirected page to K3NA notebook:W1KM

← Older revision		Revision as of 13:55, 5 December 2009
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-	#REDIRECT [[K3NA:W1KM]]	+	#REDIRECT [[K3NA notebook:W1KM]]
	[[Category:K3NA notebook]]		[[Category:K3NA notebook]]

W1KM antennas

Eric Scace — Sat, 05 Dec 2009 13:54:51 GMT

moved [[W1KM antennas]] to [[K3NA notebook: W1KM antennas]]

New page

W1KM antennas

Eric Scace — Sat, 05 Dec 2009 13:53:27 GMT

Starting incorporating recent maintenance actions

New page

[[Category:K3NA:W1KM]]
<div style="background-color:#E0FFFF">
''Note:'' A placeholder where we are starting to accumulate information. [[User:Eric Scace|Eric K3NA]] 13:53, 5 December 2009 (UTC)
==80m 4-square==
===Maintenance log===
2009 Dec 05 Fri: NW element came down in storm of Dec 04 Thu. The NW guy anchor pole rusted out and broke. I thought I had checked all the guy anchors for rust but I evidently missed that one. It doesn’t involve much to fix and we should be able to get it up on Tuesday if it’s not windy. I have to get the ladder back down there. I think somebody else should double check the guy anchors for rust — they’re easy to replace. (Or find some scrap stainless steel pipe!) --W1KM

==10m stack==
===Maintenance log===
2009 Dec 05 Fri: I swapped out the Yaesu G1000 rotator and made up a couple of new connectors. It turns OK, but sounds like it’s straining at times. It still needs to be centered better in the rotator. In hindsight I should have rewired the cable so the motor leads use the larger diameter wires; we probably should still do this. I’ll see how it works next week when I make a major effort in the 10m contest. I took the other G1000 home and will take a look at it. --W1KM

==10m multiplier Yagi==
===Maintenance log===
2009 Dec 05 Fri: Jim, N1NK came over and did some brush clearing around the small 10 m tower. It was in danger of getting completely devoured by the vegetation. We saw a large deer resting under the tower when we went out there. --W1KM
</div>

Category:K3NA:W1KM

Eric Scace — Sat, 05 Dec 2009 13:42:58 GMT

create the category

New page

#REDIRECT [[K3NA:W1KM]]
[[Category:K3NA notebook]]

Stations

Sm2wmv — Fri, 04 Dec 2009 21:45:36 GMT

← Older revision		Revision as of 21:45, 4 December 2009
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	*[http://www.pi4cc.nl PI4CC] Contest Club PI4CC. Active since 1993		*[http://www.pi4cc.nl PI4CC] Contest Club PI4CC. Active since 1993
	*[http://www.k5zd.com/articles/PY5EG/index.html PY5EG] (by K5ZD during CQ WW CW 1998)		*[http://www.k5zd.com/articles/PY5EG/index.html PY5EG] (by K5ZD during CQ WW CW 1998)
		+	*[http://www.sj2w.se/contest/ SJ2W] (Follow the progress of building a contest station, blog style)
	*[http://www.qth.com/w0aih/ W0AIH] (located near Eau Claire, WI)		*[http://www.qth.com/w0aih/ W0AIH] (located near Eau Claire, WI)
	*[http://www.k1ra.us/?page_id=3 W3LPL] and [http://www.n3aln.com/w3lpl.htm W3LPL Open House 2009]		*[http://www.k1ra.us/?page_id=3 W3LPL] and [http://www.n3aln.com/w3lpl.htm W3LPL Open House 2009]

	[[Category:Table of Contents]]		[[Category:Table of Contents]]

User:Sm2wmv

Sm2wmv — Fri, 04 Dec 2009 21:43:01 GMT

New user account

New page

Search & pounce techniques

K3tn — Wed, 02 Dec 2009 19:32:44 GMT

Show changes

K3NA:W1KM

Eric Scace — Wed, 02 Dec 2009 12:52:13 GMT

Shell for future work

← Older revision		Revision as of 12:52, 2 December 2009
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	[[Category:K3NA notebook]]		[[Category:K3NA notebook]]
	<div style="background-color:#E0FFFF">		<div style="background-color:#E0FFFF">
-	~~==Background==~~	+	This is where I keep all my notes about the design and experiences at the W1KM contesting station.

		+	'''Background:'''<br>
		+	''to be added...''

		+	'''Objectives:'''<br>
		+	''to be added...''
		+
		+	{{#categorytree:{{PAGENAME}}\|mode=pages\|hideroot}}
		+
		+	[[User:Eric Scace\|Eric K3NA]] 12:52, 2 December 2009 (UTC)
	</div>		</div>

K3NA notebook

Eric Scace — Wed, 02 Dec 2009 12:42:23 GMT

Add link to root of notebook about W1KM

← Older revision		Revision as of 12:42, 2 December 2009
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	Like many active contesters, I discovered ham radio and contesting as a young teenager. Although I did a few years of CW traffic handling (and 15 years of RTTY traffic work with Navy MARS), contesting captured my interest right from the start. Howie Mann W2FR spent many hours on the telephone coaching me to become a better operator. After moving to the Washington DC area the Potomac Valley Radio Club's members also helped me expand operating skills and technical understanding. I operated a small SO2R mountaintop station near Frederick MD for many years (with dreams curtailed by extensive travel for work), but learned much more working/operating at W4BVV, W3ABC and W3LPL. I operated 4U1ITU regularly while working with ITU technical standards committees.		Like many active contesters, I discovered ham radio and contesting as a young teenager. Although I did a few years of CW traffic handling (and 15 years of RTTY traffic work with Navy MARS), contesting captured my interest right from the start. Howie Mann W2FR spent many hours on the telephone coaching me to become a better operator. After moving to the Washington DC area the Potomac Valley Radio Club's members also helped me expand operating skills and technical understanding. I operated a small SO2R mountaintop station near Frederick MD for many years (with dreams curtailed by extensive travel for work), but learned much more working/operating at W4BVV, W3ABC and W3LPL. I operated 4U1ITU regularly while working with ITU technical standards committees.

-	While not a very diligent DX chaser, I have operated or organized some DXpeditions (and contest expeditions) to fascinating locations: FO0XX (Clipperton), 3D2XX (Rotuma), AH3C/KH5J (Jarvis), YK0A, VK9LT (Lord Howe), VK9NT (Norfolk), VK9ML (Mellish Rf), 3B9C, 3B7C, and most recently co-led VP6DX (Ducie I). Engineering and managing a successful DXpedition has its own intriguing challenges; I've learned a lot from my fellow DXpeditioners. DXpedition issues inspired more than a few of my lab notebook projects.	+	While not a very diligent DX chaser, I have operated with or organized some DXpeditions (and contest expeditions) to fascinating locations: FO0XX (Clipperton), 3D2XX (Rotuma), AH3C/KH5J (Jarvis), YK0A, VK9LT (Lord Howe), VK9NT (Norfolk), VK9ML (Mellish Rf), 3B9C, 3B7C, and most recently co-led VP6DX (Ducie I). Engineering and managing a successful DXpedition has its own intriguing challenges; I've learned a lot from my fellow DXpeditioners. DXpedition issues inspired more than a few of my lab notebook projects.

	During 1997-2001 I lived in downtown Moscow, Russia (R3/K3NA), close to the Kremlin and just around the corner from the Russian Federation's equivalent to the USA FCC headquarters. Now I live in central Cambridge, Massachusetts, midway between Harvard University and MIT.		During 1997-2001 I lived in downtown Moscow, Russia (R3/K3NA), close to the Kremlin and just around the corner from the Russian Federation's equivalent to the USA FCC headquarters. Now I live in central Cambridge, Massachusetts, midway between Harvard University and MIT.
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	Exploring more effective ways of solving problems, ways that differ from the standard approaches, particularly intrigues me. You'll probably see that inclination in my notebook.		Exploring more effective ways of solving problems, ways that differ from the standard approaches, particularly intrigues me. You'll probably see that inclination in my notebook.

-	'''My station:''' My city home site, with its urban QRN levels, does not encourage a large antenna farm. Fortunately, when I first joined the Yankee Clipper Contest Club, Greg Cronin W1KM invited me to work with the small team at his station. ~~I plan to write more~~ about the W1KM ~~site elsewhere in the ''Contesting Compendium'' in the near future~~.	+	'''My station:''' My city home site, with its urban QRN levels, does not encourage a large antenna farm. Fortunately, when I first joined the Yankee Clipper Contest Club, Greg Cronin W1KM invited me to work with the small team at his station. In hopes that others can both benefit from our experiences, and suggest/implement further improvements, information about the design of this contesting station is found [[K3NA:W1KM\|here]].

-	[[User:Eric Scace\|Eric K3NA]] 04:34, ~~25 May~~ 2009 (UTC)	+	[[User:Eric Scace\|Eric K3NA]] 12:42, 2 December 2009 (UTC)
	\|}		\|}

	</div>		</div>

K3NA:W1KM

Eric Scace — Wed, 02 Dec 2009 12:36:42 GMT

Root page for data about W1KM station design

New page

[[Category:K3NA notebook]]
<div style="background-color:#E0FFFF">
==Background==

</div>

ARRL Sweepstakes

K3tn — Mon, 30 Nov 2009 13:21:56 GMT

Sweepstakes Etiquette:

← Older revision		Revision as of 13:21, 30 November 2009
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	*'''Just because you own two radios doesn’t mean you own two frequencies'''. If you are operating SO2R and don’t respond to a legitimate “double QRL?” because you were off on the other radio trying to break the VE8 pileup, that frequency is up for grabs.		*'''Just because you own two radios doesn’t mean you own two frequencies'''. If you are operating SO2R and don’t respond to a legitimate “double QRL?” because you were off on the other radio trying to break the VE8 pileup, that frequency is up for grabs.
	*'''Send CW at the code speed of the other operator, or the fastest you are comfortable copying – whichever is '''<u>'''lower'''</u>. If you answer someone CQing at 35 wpm, but are only able to copy 20 wpm, reply at 20 wpm. If you are sending CQ at 35 wpm and someone responds at 20 wpm, slooow down to something near the other station’s code speed.Hitting Page Down or twisting the K1EL knob a bit isn't that hard. Exception: on Sunday, everyone slows down their CQ code speed to attract casual operators. If you hear a buddy calling CQ at 20 wpm and you know they copy 35 wpm, feel free to call them at 45wpm.		*'''Send CW at the code speed of the other operator, or the fastest you are comfortable copying – whichever is '''<u>'''lower'''</u>. If you answer someone CQing at 35 wpm, but are only able to copy 20 wpm, reply at 20 wpm. If you are sending CQ at 35 wpm and someone responds at 20 wpm, slooow down to something near the other station’s code speed.Hitting Page Down or twisting the K1EL knob a bit isn't that hard. Exception: on Sunday, everyone slows down their CQ code speed to attract casual operators. If you hear a buddy calling CQ at 20 wpm and you know they copy 35 wpm, feel free to call them at 45wpm.
-	*'''Take the time to make your .wav or DVK files match your mike audio and natural timing''' - the ability to used recorded voice for sending that looong SS exchange is a great convenience, but sounding like a robotic talking elevator is just not attractive. It takes a lot of time to get those individual number and letter files sounding natural. If you don't have the time, just stick with recording the ''CQ ''and ''Thanks, QRZ'' messages, and the unchanging parts of the exchange - and even on those take the time to have the levels and sound quality match your MIC audio.	+	*'''Take the time to make your .wav or DVK files match your mike audio and natural timing''' - the ability to used recorded voice for sending that looong SS exchange is a great convenience, but sounding like a robotic talking elevator is just not attractive. It takes a lot of time to get those individual number and letter files sounding natural. If you don't have the time, just stick with recording the ''CQ ''and ''Thanks, QRZ'' messages, and the unchanging parts of the exchange - and even on those take the time to have the levels and sound quality match your MIC audio. See the Contesting Wiki write-up on [http://wiki.contesting.com/index.php/Transmit_audio_adjustment Transmitter Audio Adjustment].
-	*'''Avoid begging for those last sections on the Packetcluster''' - if you need VE8, do a ''sh/dx/10 ve8'' vs''ANN Please spot NT for my sweeeep!!!'' Not a big deal, but keeping the Cluster clutter down during a contest is always a good thing.	+	*'''Avoid begging for those last sections on the Packetcluster''' - if you need VE8, do a ''sh/dx/10 ve8'' vs ''ANN Please spot NT for my sweeeep!!!'' Not a big deal, but keeping the Cluster clutter down during a contest is always a good thing.
	*'''Take time to explain things to operators who are confused.''' In sailing races, if one ship is sinking the other ships stop racing to help them out. Sweepstakes is often the first contest many US operators try out – a bad experience in SS may sour them on contesting. If you run across a station that doesn’t understand these rules of SS “etiquette,” take the time to give them some tips.<br>		*'''Take time to explain things to operators who are confused.''' In sailing races, if one ship is sinking the other ships stop racing to help them out. Sweepstakes is often the first contest many US operators try out – a bad experience in SS may sour them on contesting. If you run across a station that doesn’t understand these rules of SS “etiquette,” take the time to give them some tips.<br>
-	</blockquote>	+	</blockquote>
		+
	==== Specialty Strategies ====		==== Specialty Strategies ====

User:Hk1kyr

Hk1kyr — Mon, 30 Nov 2009 02:20:59 GMT

New user account

New page

Main Page

N4zr — Sun, 29 Nov 2009 16:22:36 GMT

← Older revision		Revision as of 16:22, 29 November 2009
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	{\| align="right" border="1"		{\| align="right" border="1"
	\|width="256" \| '''New and Revised Articles''' <br>		\|width="256" \| '''New and Revised Articles''' <br>
		+
		+	Added K3NA's [[Transmit audio adjustment]]

	Added N2IC's [[N1MM Logger Sprint Tips]]		Added N2IC's [[N1MM Logger Sprint Tips]]

Transmit audio adjustment

N4zr — Sun, 29 Nov 2009 16:19:54 GMT

More Windows configuration:

← Older revision		Revision as of 16:19, 29 November 2009
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	Finally, use the Windows volume control program’s Options menu to open the Properties dialog. In that dialog, after selecting “playback”, uncheck every playback source except for “microphone” and “wave”. As was done for recording, you want to eliminate signals from any unnecessary audio sources.		Finally, use the Windows volume control program’s Options menu to open the Properties dialog. In that dialog, after selecting “playback”, uncheck every playback source except for “microphone” and “wave”. As was done for recording, you want to eliminate signals from any unnecessary audio sources.
		+
		+	[[Image:Xmit_audio_Fig_7.jpg\|left]]

	====Setting controls====		====Setting controls====

File:Xmit audio Fig 7.jpg

N4zr — Sun, 29 Nov 2009 16:18:30 GMT

uploaded a new version of "[[File:Xmit audio Fig 7.jpg]]"

New page

Transmit audio adjustment

N4zr — Sun, 29 Nov 2009 16:16:33 GMT

More Windows configuration:

← Older revision		Revision as of 16:16, 29 November 2009
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	====More Windows configuration====		====More Windows configuration====
	Open the Settings\Control Panel\Sounds and Audio Devices properties dialog in Windows. Click the Sounds tab in this dialog, and select the “no sounds” sound scheme; see Figure 6. This prevents accidental transmission of Windows’ sound effects over the air.		Open the Settings\Control Panel\Sounds and Audio Devices properties dialog in Windows. Click the Sounds tab in this dialog, and select the “no sounds” sound scheme; see Figure 6. This prevents accidental transmission of Windows’ sound effects over the air.
		+	[[Image:Xmit audio Fig 6.jpg\|left]]

	Depending on the capabilities of your soundcard, this properties dialog box may show other tabs or buttons used to control equalizers, quadraphonic (or more) sound channels, and other specialized functions. Try to disable as many of these special functions as possible. When you cannot disable a function, set its parameters for neutral or minimal effect on the output. For example, set an equalizer function to 0 dB across the spectrum.		Depending on the capabilities of your soundcard, this properties dialog box may show other tabs or buttons used to control equalizers, quadraphonic (or more) sound channels, and other specialized functions. Try to disable as many of these special functions as possible. When you cannot disable a function, set its parameters for neutral or minimal effect on the output. For example, set an equalizer function to 0 dB across the spectrum.

File:Xmit audio Fig 6.jpg

N4zr — Sun, 29 Nov 2009 16:15:28 GMT

uploaded a new version of "[[File:Xmit audio Fig 6.jpg]]"

New page

Transmit audio adjustment

N4zr — Sun, 29 Nov 2009 15:02:42 GMT

Preserving signal to noise ratios:

← Older revision		Revision as of 15:02, 29 November 2009
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	In my case, using the soundcard’s mic boost control and setting the mic volume to ¼ of full-scale produced the desired en-coding range. Figure 5 shows the resulting recording of our team’s callsign in the most recent ARRL DX phone contest. The voice peaks at around 80% of the A/D converter encoding range. Note the low signal level between syllables, indicating a quiet background noise level; more about this later.		In my case, using the soundcard’s mic boost control and setting the mic volume to ¼ of full-scale produced the desired en-coding range. Figure 5 shows the resulting recording of our team’s callsign in the most recent ARRL DX phone contest. The voice peaks at around 80% of the A/D converter encoding range. Note the low signal level between syllables, indicating a quiet background noise level; more about this later.
		+
		+
		+	[[Image:Xmit_audio_Fig_5.jpg‎\|left]]

	===Soundcard line output audio chain===		===Soundcard line output audio chain===

File:Xmit audio Fig 5.jpg

N4zr — Sun, 29 Nov 2009 15:01:12 GMT

uploaded a new version of "[[File:Xmit audio Fig 5.jpg]]"

New page

Transmit audio adjustment

N4zr — Sun, 29 Nov 2009 15:00:34 GMT

Preserving signal to noise ratios:

← Older revision		Revision as of 15:00, 29 November 2009
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	Most soundcards contain a “mic boost” control, accessible via the Windows volume control dialog. Click the “Advanced” button under the mic volume control’s slider (Figure 4). If your volume control does not show an “Advanced” button, turn on the Advanced Controls option under the Options pull-down menu.		Most soundcards contain a “mic boost” control, accessible via the Windows volume control dialog. Click the “Advanced” button under the mic volume control’s slider (Figure 4). If your volume control does not show an “Advanced” button, turn on the Advanced Controls option under the Options pull-down menu.
		+
		+	[[Image:Xmit_audio_Fig_4.jpg‎\|left]]

	In my case, using the soundcard’s mic boost control and setting the mic volume to ¼ of full-scale produced the desired en-coding range. Figure 5 shows the resulting recording of our team’s callsign in the most recent ARRL DX phone contest. The voice peaks at around 80% of the A/D converter encoding range. Note the low signal level between syllables, indicating a quiet background noise level; more about this later.		In my case, using the soundcard’s mic boost control and setting the mic volume to ¼ of full-scale produced the desired en-coding range. Figure 5 shows the resulting recording of our team’s callsign in the most recent ARRL DX phone contest. The voice peaks at around 80% of the A/D converter encoding range. Note the low signal level between syllables, indicating a quiet background noise level; more about this later.

File:Xmit audio Fig 4.jpg

N4zr — Sun, 29 Nov 2009 14:58:52 GMT

uploaded a new version of "[[File:Xmit audio Fig 4.jpg]]"

New page

Transmit audio adjustment

N4zr — Sun, 29 Nov 2009 14:55:47 GMT

Preserving signal to noise ratios:

← Older revision		Revision as of 14:55, 29 November 2009
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	At the start of this project, I reasoned that employing the microKeyer’s mic preamp (point 2 in Figure 1) would further help to achieve that aim.<ref>I understand that Icom radios support electret mic elements; these elements require a DC bias voltage for proper operation. Soundcards provide this bias voltage routinely. The microKeyer mic preamp does not provide a bias voltage and cannot support electret mics.</ref> By boosting the mic signal levels close to the mic, any stray noise picked up in subsequent cabling would have little impact on the signal to noise ratio.		At the start of this project, I reasoned that employing the microKeyer’s mic preamp (point 2 in Figure 1) would further help to achieve that aim.<ref>I understand that Icom radios support electret mic elements; these elements require a DC bias voltage for proper operation. Soundcards provide this bias voltage routinely. The microKeyer mic preamp does not provide a bias voltage and cannot support electret mics.</ref> By boosting the mic signal levels close to the mic, any stray noise picked up in subsequent cabling would have little impact on the signal to noise ratio.

-	Without this preamp, the voice peaks on the cable between the microKeyer and the soundcard mic input jack reached 150 mVP-P. (Galvanic isolation, discussed below, accounts for the loss from the 200 mVP-P mic output levels.) Routing the signal through the preamp produced a very healthy 2 VP-P on voice peaks, about +20 dB gain.	+	Without this preamp, the voice peaks on the cable between the microKeyer and the soundcard mic input jack reached 150 mVP-P.
		+
		+	[[Image:Xmit_audio_Fig_3.jpg‎\|left]]
		+
		+	(Galvanic isolation, discussed below, accounts for the loss from the 200 mVP-P mic output levels.) Routing the signal through the preamp produced a very healthy 2 VP-P on voice peaks, about +20 dB gain.

	However, this 2 VP-P signal completely overwhelmed my sound-card’s D/A converter, resulting in very distorted recordings. Even setting the Windows volume control for the mic input (point 4 in Figure 1) at just one pixel above zero resulted in negative-going voice peaks hitting 100% of the converter’s encoding range. (Negative-going voice peaks hit the encoder more heavily than positive-going peaks. Because soundcard mic jacks applied some DC voltage between tip and sleeve, it seems plausible the card’s circuit did not fully block this DC voltage before delivering the signal to the encoder.)		However, this 2 VP-P signal completely overwhelmed my sound-card’s D/A converter, resulting in very distorted recordings. Even setting the Windows volume control for the mic input (point 4 in Figure 1) at just one pixel above zero resulted in negative-going voice peaks hitting 100% of the converter’s encoding range. (Negative-going voice peaks hit the encoder more heavily than positive-going peaks. Because soundcard mic jacks applied some DC voltage between tip and sleeve, it seems plausible the card’s circuit did not fully block this DC voltage before delivering the signal to the encoder.)

File:Xmit audio Fig 3.jpg

N4zr — Sun, 29 Nov 2009 14:54:54 GMT

uploaded a new version of "[[File:Xmit audio Fig 3.jpg]]"

New page

Transmit audio adjustment

N4zr — Sun, 29 Nov 2009 12:16:01 GMT

Microphone:

← Older revision		Revision as of 12:16, 29 November 2009
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	=== Microphone===		=== Microphone===
		+
		+	[[Image:Xmit Audio Fig 2.jpg]]

	====Making measurements====		====Making measurements====

File:Xmit Audio Fig 2.jpg

N4zr — Sun, 29 Nov 2009 12:14:23 GMT

uploaded "[[File:Xmit Audio Fig 2.jpg]]"

New page

Transmit audio adjustment

N4zr — Sun, 29 Nov 2009 12:10:15 GMT

Components of the transmit audio chain:

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	Figure 1 outlines the flow of audio. A short study reveals over a dozen locations along the audio chain where adjustments affect the quality of SSB audio on the air. No wonder stations have poor audio – so many opportunities exist to contaminate the signal! Audio, once contaminated, cannot be restored.		Figure 1 outlines the flow of audio. A short study reveals over a dozen locations along the audio chain where adjustments affect the quality of SSB audio on the air. No wonder stations have poor audio – so many opportunities exist to contaminate the signal! Audio, once contaminated, cannot be restored.

-	[[image:Xmit Audio Fig 1.jpg]]	+	[[image:Xmit Audio Fig 1.jpg\|frame\|Figure 1: Flow of transmitted audio at W1KM. The numbered points identify key controls affecting transmission quality.]]

-	The general strategy for setting all these adjustments proceeds	+
-	as follows:	+
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		+	The general strategy for setting all these adjustments proceeds as follows:

	* Operator training.		* Operator training.