Posts Tagged ‘amateurradio.com’

1 Watt and a Wire… in the Attic

You can't always get what you want, but you try sometimes...

Recently I've dialed my normal 5 watts down to 1watt (one watt, singular) for all my contacts.  To throw some water on the fire I've decided to use my attic antenna which weaves all around my metal ductwork and electrical wiring.   Mostly this was to prove a point to myself but it may be enlightening to deed restricted hams that they can use a qrp radio and an attic antenna successfully.

Key lineup... Palm Single (paddle), Vibroplex Bug (circa 1970s), Kent Hand key

It only seems pointless until you try

Calling CQ with 1w QRPp into a poor attic antenna isn't as pointless as it would seem.  I didn't have to wait long when calling CQ before I got an answer most of the time.  

Now am I going to bust a pileup with 1 watt ?  Possibly not but I think that my assumptions about both how much power I need and how big an antenna I need are usually out of proportion with reality.

1 mighty watt

My assumptions are often incorrect

I made QSOs on 30m, 20m, 17m and 10m this morning all at 1 watt.  The solar conditions report was not really fantastic, especially for 10m.  Yet 1 watt through the attic antenna bagged the only DX I heard on 10m.  I had a couple of other multiple exchange contacts on 20m, 17m and one good old fashioned 25 minute long ragchew on 30m where I received a 599 report for my one watt from Bob (NR8M) in Ohio.  Admittedly, Bob was booming in and we had good propagation to each other.

http://www.hamqsl.com/solar.html

Video

The recording below was number 4 or 5 this morning.  I wanted to post this one because I was working another QRP station in Arkansas (K5EDM) and we did NOT have great propagation to each other.  He was running 5w while I was running 1w so it was QRP to QRPp.  In the video you can see that I'm using some of the KX3's tricks to pull the signal up because there was a lot of QSB and noise (note the GEOMAGNETIC FIELD UNSETTLED in the solar report).  

I had the volume maxed and was using the RF gain control mostly.  I eventually had to turn on the preamp which really washed me in noise but I dropped the RF gain more and eventually switched in the APF (audio peaking filter) which performed magic on this contact.  Often I find that APF doesn't help but this time it made a big difference.


That's all for now

So lower your power and raise your expectations

72/73
Richard N4PBQ

Doctor and patient are doing fine

A few days ago, I went out to the car as I usually do, for some lunchtime QRP.  In my haste to get everything put away after I was done, I inadvertently knocked the external battery off the car seat onto the floor. The KX3 started to move, as it was still attached, but a quick hand stopped it, and all was well. Or so I thought.

Gear on the backseat of the Jeep.

Yesterday, I went out again, and this time the KX3 wouldn't turn on. No problem, I thought to myself, the battery was probably on its way out, as it has been a while since I have given it its last drink.  So last evening, while I was attending a CERT class on animal handling during declared emergencies, I had the battery plugged in at home, charging.

When I got home, around 10:00 PM, I tried reconnecting the battery to the KX3 to see if everything was OK.  Still no sign of life - my KX3 was still flat lining..  Hmmmmmm ........ could the battery have gone totally bad?

I carried the radio down to the shack 13.8V power supply.  Viola!  It turned on! 

And then immediately turned off.


My brain went into over drive. What the %(#@*#$ was going on ?!?

I dread sending stuff out for repair.  Don't know why, I just do.  I was in the professional photographic electronics repair biz for over 20 years. I have fixed studio strobes costing well over $12,000.00.  I have taken apart digital camera backs that cost more than a Mercedes Benz. I have stared down banks of charged capacitors storing up enough electrons to supply 6,400 Joules of energy in one pop - certainly I should be able to figure out a relatively minor KX3 repair? Right?

I rolled up my sleeves and got down to it.  Obviously, this was a power problem.  But why was the rig shutting down so quickly?  Internal short?  Bad connection somewhere? Then I noticed that if I wiggled the power plug a certain way, the radio would stay on.  My mind immediately flashed back to the battery falling incident from the other day.  I must have done something to the power socket.

The power socket is the black, boxy thing to the right.

The advantage of building the KX3 (if that's what you want to call it) is that you know how it goes together, so you're not frightened at the prospect of taking it apart.  You've seen it in all its naked glory and you lovingly put it together at least once, right?  So what's the big deal in taking it apart?

Well, when you built it roughly five years ago, some of the finer details of how it went together get muddled up in the old memory banks.  That's why it's good to never toss the build manual!  Within about 5 -7 minutes I had it apart and had the display circuit in my hand.  A little extra light and a lot of extra magnification from a magnifying glass confirmed my suspicion.

The power socket is a surface mount device, just about like everything else on that display/control circuit board. The weight of the battery tugged the socket enough to unmoor it from its assigned, tinned pads.  When I would wiggle the connector "down" towards the circuit board, everything worked.  As soon as I let downward pressure go, the connector would break contact from the circuit board again and the radio would appear dead.

I ran upstairs for a pair of scrubs and to wash my hands to prep for surgery. NO! Just kidding!


I changed my soldering station tip to the skinniest one that I have for when I work on SMD devices and I re-soldered that connector onto its pads. I took great care to add just a little "extra" solder just to make sure the connection is good, solid and won't come apart so easily in the future.

I hastily (I'll get back to that in a minute) put everything together and fired the radio up. Fixed! Problem solved! High fives and happy dances all around!

I will have to go back sometime over the weekend to remove the front plexiglass display window, though.  In my haste, I wasn't so careful about finger prints.  I'll have to go back and clean that up.  Yes, I know ...... call me anal.  I can't help it!

But as this blog post says - the patient (and more importantly, the doctor) are doing just fine! And even more importantly - no return trip to Aptos!

PROGNOSIS: Excellent!  Today's lunchtime QRP session netted the following:

N0TA - SOTA peak W0C/PR-082 (Squaw Mountain) in CO on 20 Meters.
VP5/AC0W - Turks and Caicos Islands on 20 Meters
CT9/OM3RM - Madeira Island on 20 Meters.
PJ2/NF9V - Curacao on 15 Meters.

I chased KH7Y in Hawaii who was absolutely booming into NJ on 15 Meters, but could not make myself heard. Just goes to show, you can't win them all!

72 de Larry W2LJ
QRP - When you care to send the very least!

Doctor and patient are doing fine

A few days ago, I went out to the car as I usually do, for some lunchtime QRP.  In my haste to get everything put away after I was done, I inadvertently knocked the external battery off the car seat onto the floor. The KX3 started to move, as it was still attached, but a quick hand stopped it, and all was well. Or so I thought.

Gear on the backseat of the Jeep.

Yesterday, I went out again, and this time the KX3 wouldn't turn on. No problem, I thought to myself, the battery was probably on its way out, as it has been a while since I have given it its last drink.  So last evening, while I was attending a CERT class on animal handling during declared emergencies, I had the battery plugged in at home, charging.

When I got home, around 10:00 PM, I tried reconnecting the battery to the KX3 to see if everything was OK.  Still no sign of life - my KX3 was still flat lining..  Hmmmmmm ........ could the battery have gone totally bad?

I carried the radio down to the shack 13.8V power supply.  Viola!  It turned on! 

And then immediately turned off.


My brain went into over drive. What the %(#@*#$ was going on ?!?

I dread sending stuff out for repair.  Don't know why, I just do.  I was in the professional photographic electronics repair biz for over 20 years. I have fixed studio strobes costing well over $12,000.00.  I have taken apart digital camera backs that cost more than a Mercedes Benz. I have stared down banks of charged capacitors storing up enough electrons to supply 6,400 Joules of energy in one pop - certainly I should be able to figure out a relatively minor KX3 repair? Right?

I rolled up my sleeves and got down to it.  Obviously, this was a power problem.  But why was the rig shutting down so quickly?  Internal short?  Bad connection somewhere? Then I noticed that if I wiggled the power plug a certain way, the radio would stay on.  My mind immediately flashed back to the battery falling incident from the other day.  I must have done something to the power socket.

The power socket is the black, boxy thing to the right.

The advantage of building the KX3 (if that's what you want to call it) is that you know how it goes together, so you're not frightened at the prospect of taking it apart.  You've seen it in all its naked glory and you lovingly put it together at least once, right?  So what's the big deal in taking it apart?

Well, when you built it roughly five years ago, some of the finer details of how it went together get muddled up in the old memory banks.  That's why it's good to never toss the build manual!  Within about 5 -7 minutes I had it apart and had the display circuit in my hand.  A little extra light and a lot of extra magnification from a magnifying glass confirmed my suspicion.

The power socket is a surface mount device, just about like everything else on that display/control circuit board. The weight of the battery tugged the socket enough to unmoor it from its assigned, tinned pads.  When I would wiggle the connector "down" towards the circuit board, everything worked.  As soon as I let downward pressure go, the connector would break contact from the circuit board again and the radio would appear dead.

I ran upstairs for a pair of scrubs and to wash my hands to prep for surgery. NO! Just kidding!


I changed my soldering station tip to the skinniest one that I have for when I work on SMD devices and I re-soldered that connector onto its pads. I took great care to add just a little "extra" solder just to make sure the connection is good, solid and won't come apart so easily in the future.

I hastily (I'll get back to that in a minute) put everything together and fired the radio up. Fixed! Problem solved! High fives and happy dances all around!

I will have to go back sometime over the weekend to remove the front plexiglass display window, though.  In my haste, I wasn't so careful about finger prints.  I'll have to go back and clean that up.  Yes, I know ...... call me anal.  I can't help it!

But as this blog post says - the patient (and more importantly, the doctor) are doing just fine! And even more importantly - no return trip to Aptos!

PROGNOSIS: Excellent!  Today's lunchtime QRP session netted the following:

N0TA - SOTA peak W0C/PR-082 (Squaw Mountain) in CO on 20 Meters.
VP5/AC0W - Turks and Caicos Islands on 20 Meters
CT9/OM3RM - Madeira Island on 20 Meters.
PJ2/NF9V - Curacao on 15 Meters.

I chased KH7Y in Hawaii who was absolutely booming into NJ on 15 Meters, but could not make myself heard. Just goes to show, you can't win them all!

72 de Larry W2LJ
QRP - When you care to send the very least!

The need for speed in CW

CW QSO speed statistics... 

As I continue on my Morse Code Journey I have been using a desktop application called Morse News to work on my code comprehension of natural language sentences for ragchew training. I set the program to send at speeds higher than I can copy to stretch me.  Presently I have it set at 26wpm character speed and 23wpm Code speed.  I can usually figure out what the news story is talking about but I miss a lot of the specifics.



I was a kid in the 1970s when Speed Racer was a popular cartoon

The need for speed

Currently I'm OK working up to 20wpm qsos as long as the other station has good spacing.  Sometimes I lose the thread or the specifics in a ragchew at 20wpm and I just ask them PSE AGN? 

In sprints I can copy a callsign sent at 25wpm to 30wpm if I hear it a few times but that's no good for real contests where you need to catch that call sent at 30-40wpm sent the first time.  My friend AA4XX has asked me to help him in multi-op contests but I know he is sending around 30wpm and I just can't hang there at this stage in my Morse Code journey.

Statistics show 25wpm is the magic number

So it got me to wondering what was the actual "average" qso speed.  I downloaded days of raw data from Reverse Beacon Network.  RBN collects the call sign, the SNR and the SPEED.  The raw files contained between 40 to 50 thousand CW CQ calls logged each day after I filtered out other modes.

The average speed from RBN CW logs worked out to exactly 25wpm.  The standard deviation was 5.34wpm which would mean most of the time you would expect to work stations between 20wpm and 30wpm.  That seems reasonable and matches what I seem to hear on air.  These numbers are from the CQ calls themselves and are only measuring character spacing speed so the code spacing is likely a bit lower in most cases and for ragchews is likely averaging 2 to 5 wpm lower than the actual sent character speed.  Since I am not much interested in serious contesting at this stage in my hobby going over 30wpm isn't on my radar.  

So based on those calculated CW speed statistics from RBN data if I can reach the point where I am comfortable in a 25wpm ragchew I should be content (for a while)

That's all for now.

So lower your power and raise your speed.... err expectations

72/73
Richard, N4PBQ

Making use of Elecraft Mini-module Kits

Connecting the bits and bobs

I have enjoyed building Elecraft Mini-Module kits.  Now to put them to use...

Elecraft Mini-Module Kits

What to do?

I built the kits as part of my learning adventure and to improve my soldering skills.  It's also helped me learn to follow instructions better (my wife says I need to work on learning to follow instructions).  But ultimately these modules are intended to be useful, and in my case they work nicely to when operating my old Ten-Tec Century/21.

My Ten Tec Century/21 is a 1970s CW-only, low(ish) power rig originally intended for Novice license holders of the time.  It has no RF output meter or SWR meter.  It has poor filtering/selectivity compared to modern radios and its analog tuning dial is a bit vague so you generally only know your frequency within 5 kHz. 

The mini-module kits prove useful. I employ the W1 Wattmeter to determine my power output and SWR; the CP1 directional coupler is used to send a 20db attenuated signal to a frequency counter to determine operating frequency, and the AF1 Audio Filter makes operating near adjacent CW signals more pleasant by providing a narrow audio-band-pass filter.  The result signal can be transmitted through a LDG tuner into the BL2 switchable balun connected to my attic Doublet.

Bring out your cables

All these independent modules need to be connected, so tying the bits and bobs together requires a few coax jumpers to route the RF around:
  1. UHF to BNC from the radio to the W1 Power meter
  2. BNC to BNC From the W1 Power meter to the CP1 coupler
  3. BNC to UHF From the CP1 coupler J1 input to switched T1 output to frequency counter
  4. BNC to UHF From the CP1 coupler J2 output to the tuner
And other cables:
  1. Serial cable from the W1 Power meter to the computer
  2. 12v power cables for the W1 and AF1 (unless I want to use 9V batteries)
  3. Audio cable from the TenTec C21 to the AF1
So it's definitely not a neat and tidy setup at present. I plan to arrange things more neatly and possibly place the W1, CP1 and frequency counter into a single box. But for now it's fine and I like the flexibility to switch things around or pull a module out to use somewhere else as the mood strikes.

AF1 Audio Filter making crowded band operations pleasurable
  
CP1 Directional Coupler sending off 20dB attenuated signal to the frequency counter

Frequency Counter fed by the CP1 directional coupler.

W1 Power Meter sending its measurement off to the computer

W1 Power Meter Output to Computer

The W1 has a serial output to a PC for use with the Elecraft W1 software.  The software can both configure the meter and display more detail than can be determined from the LEDs.   Source code is supplied and the command set is documented so it would be easy to write your own software for this.

The W1 power meter LEDs give you relatively discrete output information for the lower two ranges (0.1w to 1.4w) and (1.5w to 14w).  But in the high range (over 14w) the LEDs are only displaying 10 watt intervals.  For instance in the high range, when the second LED is lit you don't know if your operating just 20 watts or 29 watts.  It won't trip the next LED until it crosses the 10 watt boundary in the high range so it can be useful to look at the measurement on the computer if you are operating QRO.   I'm not complaining.  I understand that the meter is primarily intended as a QRP meter and for QRP power (less than 15 watts) it offers plenty of information.
Here I brought the TenTec Century/21 up to nearly full input drive (55-60 watts) to see what it could output. The rig probably had a few more watts left in there but I didn't want to push it because I haven't gotten around to replacing some of the out of spec components in the internal power supply.  I normally use this radio under 10 watts (I look for about 30 watts input on the drive meter) but I was curious to see what the old girl could do since I had the meter hooked up to the computer display.
Measuring maximum RF output from the Ten Tec Century/21
The computer interface is a nice touch and the ability to modify the source code to suit is a plus.

Nits and Quibbles

My antenna's native SWR at 15m (~21.08MHz) is around 2.5 so it requires tuning (impedance matching).  After my LDG auto tuner spends a ridiculous amount of time trying to find a match it settles at 1.7 SWR according to the W1 Wattmeter, while the indication on the Autotuner is that it believes the SWR is 1.5 or better, while the radio on the other side of the W1 meter sees a SWR over 2.5.  I only see this behavior on 15m so I think there is some strange impedance reaction occurring in the W1 wattmeter that is changing the reactance on the jumper to the radio.  I've tried a few different jumpers, swapping jumpers, etc.  But it always presents an abnormally high SWR to the radio at 15m.  Now when I transmit into a dummy load I don't see this behavior, so it is some combination of SWR / reactance present at W1 that causes a impedance mismatch downstream toward the radio.  I have more investigating to do but for now I am choosing to not use the W1 Wattmeter in-line when operating on 15m.

The CP1 directional coupler is not entirely transparent and raises the SWR by a bit as signal passes through it.  You would expect there to be losses according to the -20 db taps (one forward and one reverse).  This should work out to about 0.08% loss but I wouldn't expect it to raise the SWR. It adds about 0.1 to your SWR  and occurs even if the forward and reverse couplers are switched "off" and shunt their respective loads to the on-board 50 ohm resistors.  I'm unsure what accounts for that slight SWR bump but be aware that CP1 contributes some very small losses.

Summary

So the Elecraft Mini-modules are fun to build; and with enough jumper cables, can be combined for experiments and general augmentation of other equipment in your shack.  So go out there, build some kits and experiment.  It's a rewarding experience.

I'm trying to decide what I'm going to build next.

That's all for now... 

So lower your power and raise your expectations

73/72

Richard, N4PBQ

Smartphones

I was prompted to write this because of the latest poll on eHam.  It's about smart phones and Amateur Radio apps.  Of course, it devolved from being anything useful into a bunch of curmudgeons blasting the topic to smithereens.

"What do you need a smart phone for anyway? I detest them, they are the mark of the Beast - the Devil's plaything, they are everything that is wrong with society! I use a real radio that has knobs ...... remember what those are?"  I am paraphrasing, of course.  ;-)

And so on, and so on, and so on.  Sigh - heavy sigh.

It's a tool, guys ...... just another tool in the Ham radio arsenal, get it?

I have a pre-owned (sound so much better than "used") Samsung Galaxy S3, which I recently picked up on eBay.  It's my first personal 4G cell phone. (I know, forever behind the times.)  Even though it's an older model, it's in excellent shape and I'm familiar with the S3, as my work-issued cell phone used to be an S3.  For work, they recently upgraded me to an iPhone 5s, which I don't like (or use) - but this post is not about that.

My Galaxy S3 is a great companion for portable QRP ops. It's works much better than the Motorola Droid 2 that I previously used. It has more system memory, so it doesn't lock up or lag on me, like the Droid 2 used to. I have the following Amateur Radio apps on it:

HamLog
SOTAwatch
Morse Trainer by Wolphi
QRZDroid
DX Cluster


HamLog is great! It's easy to use and has a lot of features. If I'm not in a pileup situation (ragchew mode, or even causal sprint operation), it's easy enough for me to type in my contacts. In a hectic pileup situation (think activating NPOTA or the Skeeter Hunt), where things are happening fast and furious, I get flustered a bit. I can start out logging on the cell phone, but inevitably, I end up getting fumble-fingered and have to resort to old school - paper and pencil.  If I'm near a wi-fi source (I have a very limited monthly data allowance, so my data connection is always off), it will even look up the names and QTHs of the operators that I am currently working.  I can easily export the log to an ADIF file, so that I can add my portable ops contacts to my main log on Log4OM.

SOTAwatch - turn it on and it shows you the current activations. Call signs, peak, frequency and mode. It has other features which I haven't even explored yet.

Morse Trainer - This is one of the best Morse Code trainers out there IMHO.  It will allow Morse to be sent as fast as 60 WPM.  I keep mine set to a speed of about 40 WPM and have it send regular words.  I try to listen to some code practice several times a week in my never ending goal to become an even more competent CW op. Boy, 25 WPM sure sounds easy-peasy after listening to 40 WPM for a while!

QRZDroid - QRZ.com in an app. Easy call sign look up.

DX Cluster - Very helpful in tracking NPOTA stations.  The only drawback with DX Cluster is that you can filter it for either all HF bands or mono-bands. It would be nice if I could filter say, 20 and 17 Meters in one shot. But, hey, if wishes were nickels, I'd be a rich man. Wish I was smart enough to write apps like these, then maybe I would be a rich man!

The bottom line is that a smart phone can be a useful tool to compliment and enhance your overall Amateur Radio experience. It's not a replacement or any other kind of bogeyman. It is what you make of it.

72 de Larry W2LJ
QRP - When you care to send the very least!

Smartphones

I was prompted to write this because of the latest poll on eHam.  It's about smart phones and Amateur Radio apps.  Of course, it devolved from being anything useful into a bunch of curmudgeons blasting the topic to smithereens.

"What do you need a smart phone for anyway? I detest them, they are the mark of the Beast - the Devil's plaything, they are everything that is wrong with society! I use a real radio that has knobs ...... remember what those are?"  I am paraphrasing, of course.  ;-)

And so on, and so on, and so on.  Sigh - heavy sigh.

It's a tool, guys ...... just another tool in the Ham radio arsenal, get it?

I have a pre-owned (sound so much better than "used") Samsung Galaxy S3, which I recently picked up on eBay.  It's my first personal 4G cell phone. (I know, forever behind the times.)  Even though it's an older model, it's in excellent shape and I'm familiar with the S3, as my work-issued cell phone used to be an S3.  For work, they recently upgraded me to an iPhone 5s, which I don't like (or use) - but this post is not about that.

My Galaxy S3 is a great companion for portable QRP ops. It's works much better than the Motorola Droid 2 that I previously used. It has more system memory, so it doesn't lock up or lag on me, like the Droid 2 used to. I have the following Amateur Radio apps on it:

HamLog
SOTAwatch
Morse Trainer by Wolphi
QRZDroid
DX Cluster


HamLog is great! It's easy to use and has a lot of features. If I'm not in a pileup situation (ragchew mode, or even causal sprint operation), it's easy enough for me to type in my contacts. In a hectic pileup situation (think activating NPOTA or the Skeeter Hunt), where things are happening fast and furious, I get flustered a bit. I can start out logging on the cell phone, but inevitably, I end up getting fumble-fingered and have to resort to old school - paper and pencil.  If I'm near a wi-fi source (I have a very limited monthly data allowance, so my data connection is always off), it will even look up the names and QTHs of the operators that I am currently working.  I can easily export the log to an ADIF file, so that I can add my portable ops contacts to my main log on Log4OM.

SOTAwatch - turn it on and it shows you the current activations. Call signs, peak, frequency and mode. It has other features which I haven't even explored yet.

Morse Trainer - This is one of the best Morse Code trainers out there IMHO.  It will allow Morse to be sent as fast as 60 WPM.  I keep mine set to a speed of about 40 WPM and have it send regular words.  I try to listen to some code practice several times a week in my never ending goal to become an even more competent CW op. Boy, 25 WPM sure sounds easy-peasy after listening to 40 WPM for a while!

QRZDroid - QRZ.com in an app. Easy call sign look up.

DX Cluster - Very helpful in tracking NPOTA stations.  The only drawback with DX Cluster is that you can filter it for either all HF bands or mono-bands. It would be nice if I could filter say, 20 and 17 Meters in one shot. But, hey, if wishes were nickels, I'd be a rich man. Wish I was smart enough to write apps like these, then maybe I would be a rich man!

The bottom line is that a smart phone can be a useful tool to compliment and enhance your overall Amateur Radio experience. It's not a replacement or any other kind of bogeyman. It is what you make of it.

72 de Larry W2LJ
QRP - When you care to send the very least!

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