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A Tale of Two Mics

29 March 2016 | by Greg KK4TIX | Leave a Comment (8)

Number 8 I’m fairly new to this amateur radio community and I’ve already learned a lot. What excites me about it, beyond making contacts, is the making of parts and equipment. Homemade or homebrew items are sprinkled liberally around the community. I appreciate what I have learned and I’m excited to learn more.

So, here’s my problem:

I went through a couple of radios, mainly mobile radios, until I found suitable base radio for starters. After my young son decided to play with my adjustable power supply, he fried my Yaesu 8900, beyond repair. I took it to a local operator, who, after careful investigation and minor repair, declared the radio dead. He offered his condolences and offered that he might be selling a radio, not that he was trying to force me to buy it. I inquired about this radio. It was a Kenwood TS-2000. Looks nice and has a lot of buttons. He told me he was going to take it to the local ham fest to sell and if it didn’t he’d make it a good deal for me.

As fate would have it, the radio didn’t sell. Indeed, he sold it to me for an undisclosed amount that was more than a good deal for me. He added an HP DPS-1200FB server power supply to avoid the incident to which my Yaesu had succumbed. I was happy and overwhelmed. This radio was more than I ever imagined, and I’m still learning about it after almost a year.

Eventually, I discovered that VOX is very useful for HF work. So, I added a cheap computer studio mic and went to work on HF. Then, there are the local nets on the local repeaters. While not forbidden to use VOX on the repeater, setting things was just a bit tricky. So, I opted to use the supplied Kenwood dynamic push-to-talk mic for repeater work.

Now, the two mics are in play. Any time I switched between the repeaters and HF, I also switched mics. I had to disconnect one and attach the other, which, besides being cumbersome, just made me worried I’d eventually mess up the connectors.

Behold! The idea for a microphone selector switch was born.

Read the rest of this post

Greg Walters, KK4TIX, is a special contributor to AmateurRadio.com and writes from Kentucky, USA.

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It’s ALIVE !

29 March 2016 | by Richard AA4OO | Leave a Comment (1)

The 1Watter 40m #551 -- Lives

The 1Watter 40m on it's inaugural QSO

Inside the enclosure

The 1Watter is a kit from kits and parts dot com

The Universal 1Watter (also called the 1H2O) is a full featured little superhet radio transceiver that you can build for about $50. It doesn't come with an enclosure, a tuning pot, speed pot or an on/off switch so that will cost extra unless you already have some in the junk bin.

Some of the features include;

1 mighty watt of output
Good selectivity from the 3 crystal filters
A VCXO tuned frequency range for the 40m band from approximately 7,020 kHz through 7,039 kHz
A built-in full functioned keyer with provision for adding a speed pot and messages

Included command button accesses the functions of the electronic keyer
Natural sounding sidetone (nicer than my Ten-Tec Century/21)

The Build

The kit is delivered in a box and inside are a couple of brown paper bags stapled together. Inside one of the bags are a couple of plastic bags with the components. The other bag contained the header kit. The ferrite toroid mix types are separated in different unmarked plastic bags so don't mix them up (the instructions tell you which bag has each mix). If anything is missing the kit supplier (Diz, W8DIZ) is very responsive.

The kit includes both SMT caps and through hole caps. I tried to solder one of the SMTs but I didn't have the right kind of tweezers to hold it in position for soldering so I used the through hole caps.

SMT and through hole caps are supplied

This is the 3rd revision of the Universal 1Watter board and I was the first to build the 40m version.

While the schematic was correct, some of the instructions weren't sorted out properly for the 40m kit. I related issues as I found them to the designer and he promptly updated the online documentation.

I soldered the components and wound toroids as I had time over a few evenings and the initial voltage tests went well.

using through hole capacitors rather than the SMTs

some of the bits and bobs

build is progressing

close up

XTAL filters give it good selectivity

Everything except the final transistor

AGC circuit

Debugging

When the build was completed I connected the rig to an antenna and heard nothing.

The keying circuit and transmitter worked fine and I verified those functions but the receiver was deaf as a stump.

Thus began a number of days of investigation. Diz (the creator of the board) guided me through a number of debugging steps.

The first recommendation was to examine and rewind the binocular toroid balun that transformed the impedance from the xtal filters to the input of the U5 oscillator. He believed that I may had wound it incorrectly. I desoldered it and rewound it but that did not resolve the issue.

He then guided me through determining if one of the filter crystals or filter capacitors was bad. I desoldered a few components as a tests but that did not resolve the issue.

There are 3 identical mixer chips on the board. I swapped them around as there was a suggestion that there were some faulty chips in one of Diz's shipments.

I then took the board to my Elmer Paul Stroud AA4XX. He had a signal generator, Oscilloscope and RF detector. He traced the RF and all looked well but we still were unable to obtain any signal through the U5 mixer. Lastly we tried disconnecting the AGC transistor to see if it was clamping it and that didn't resolve it either.

Diz asked me to return the radio to him so he could take a look. After a couple weeks he emailed me saying he thought the BFO xtal might have a problem. But he later discovered that the oscillator in U5 was not starting up. Apparently the circuit design had a low Q and needed more current to get the oscillator working. He modified the design, adding a 16k resistor to the bottom of the board on U5 to get the oscillator going. After that all was well and he shipped the board back to me.

The FIX for all those problems required an extra resistor connected across U5

Learning from problems

Being the first person to build a particular version of a kit brings its own set of challenges, especially when you're as new to kit building debugging RF problems as I am. However I'm actually glad the kit didn't work right at the initial build.

The process of debugging the board, was a great learning process. I studied the schematics and learned, as best I could, the function of each circuit so that I could better understand how to test it. During the debugging process Diz instructed me that although RF signal generators and scopes are useful you can tell a lot by touching a RF component with an inductive metal object and listening for a buzz or hum from the BFO.

So all-in-all, even though the bug in the board was not due to a error on my part, I'm glad it occurred. I understand more about superhet radio design than I did before and more than if the kit had worked right off the bat.

On the air

After receiving the board back, I hooked up the frequency XCO potentiometer, paddle, command button, audio and output potentiometer and an external speaker. I then connected a 12v battery and heard the 1H2O keyer chip announce itself at power up in Morse "1 W".

Frequency control pot on the left

Volume control, output jack, cmd pot and paddle input

You can change speeds and modify settings via the command button which I have not reviewed yet. I also plan to add the speed pot so that I can easily change keyer speed without entering the command menu.

For this first on-air excursion I was using it at the default startup 15wpm keyer speed. You can default the speed higher with a different resistor value.

I have a resistor shrink wrapped and connected in-line to the blue-white wire coiling above the radio connecting to the speed pot terminal. In essence fixing the speed at 15wpm until I add the speed pot.

Ready to transmit

On the air... I was using my paddle out of the photo to the right of the Bug

First On Air QSO

I tuned around and found a strong station at the end of a QSO near 7030 kHz.

When he sent the final dit-dit I called and WD4AXJ answered my first call. He was in TN near Knoxville, and I received a 559. We chatted for about 10 minutes. Sorry about the blurry video. I thought I'd focused.

After I recorded this video I found an open frequency and sent out my call. Very shortly thereafter KD2FSH answered my call and reported me as 599!

Whoo - hoo. 599 for my little 1Watter 40m.

I was transmitting using my 40m attic antenna. So deed restricted HAMs take note. You can build a one-watt radio and make contacts using your attic antenna. Haha.

You'll hear in the video there is some weirdness going on with the audio derived AGC. It is clamping down sometimes and is worse when I don't have the volume turned up very loud. When I began calling it clamped after every semi-break-in but didn't do it much after that. I'll have to look into that.

The AGC clamping may be a side effect of the increased gain Diz added to the BFO oscillator. I'll ask the forum.

Other than the AGC issue I'm super pleased with the little board. I touched the heat sync a couple of times after transmitting my side of the qso and it was warm but not really hot. It seems as though as long as you have a reasonable match to the antenna the power transistor should be happy.

My next steps are to get it in an enclosure and get it out to the Excalibur antenna site to hook onto that nice 40m doublet we put up a couple weekends ago. I plan to use my efficient little BLT tuner for that purpose. I will do a further review of the feature set on the keyer and record some more qsos for a later review.

Summary

The band was fairly busy and the little 1Watter did a fine job with stations on nearby frequencies. You can hear some getting around the passband but it is not bad at all. I'll do some tests to further define it's selectivity but at first glance it is far better than my old Ten-Tec Century/21.

My calls were answered quickly and I received good signal reports. It didn't sound as though the transmitter was drifting at all during the QSO. That's one advantage of using VCXO in the design. The disadvantage of using a crystal controlled oscillator for the frequency control is limited tuning range. The transmitter only has about a 18 kHz tuning range around 7030 kHz and I don't find many of the SKCC folks around that frequency but it is the QRP watering hole for 40m.

It is possible to shift the frequency with some capacitance changes but I think I'll leave it as is for a time and see how many states I can work.

Just imagine. This little $50 single band kit has good selectivity, a nice built-in keyer with a natural sounding sidetone, and lest we forget... You get a MIGHTY 1 WATT of OUTPUT. What more could a QRP ham need.

That one-watt of output was sufficient for all the QSOs I attempted tonight.

So lower your power and raise your expectations

72/73

Richard, AA4OO

UPDATE: 04/01/2016

I am still having the AGC pumping issue and others on the list have reported similar issues but only on receive. It happens to me when I key unless I turn up the volume very high. I did get it installed in a case but I still need to wire up a real power connector rather than using alligator clips.

!Watter installed in a case

UPDATE: 04/05/2016

After doing quite a bit of reading I learned that the LM386 op-amp used in the 1watter is rather notorious for audio oscillations. There are a number of suggested fixes. I went with a 4.7uf cap connecting Pin 7 on U6 (the LM386) to ground. That hasn't totally resolved the issue but it's much less pronounced now.

cap fix for LM386 oscillations

I have it in the case with all the proper plugs now (see below) so I'm happy. I've been making QSOs every day with it and it continues to amaze me and the stations that work me. It is stable as a rock with regard to frequency and the large knob with the single turn 10k pot seems to work well for tuning. I have enough control to vary the frequency slightly without having to turn it too much. The tuning range is only about 20kHz so just 3 frequency markers are plenty to let me know what frequency I'm near. The selectivity is just fantastic for such a simple little radio. Diz has created an inexpensive winner.

1Watter in enclosure with all the proper connectors for the case

Richard Carpenter, AA4OO, is a regular contributor to AmateurRadio.com and writes from North Carolina, USA. Contact him at [email protected].

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Remembering things is the hard part……

28 March 2016 | by Mike VE9KK | Leave a Comment (2)

My work station and my assistant...sleeping.

I find as most do that as you get older somethings get harder to remember! It's like that for me with ham radio at times bouncing from CW to the different digital modes can be a memory game.
Some of my memory games are:
1. Removing cables from a piece of equipment thinking I have a photographic memory....only when it comes time to re-connect the picture is blank!
2. Running digital software and an issue comes up.....I know its happened before and it's a easy fix if I could only remember the dam fix!
3. When software is not playing well together and it's a com port issue....I will be darned if I can remember what com port goes where!
4. A real good one for me is some of my software share the same virtual comports it's always a brain teaser to figure out what software can and can't work together!
It was now time to address the above issues the Easter weekend was here and I have some extra time on my hands.

Murphy strikes

To solve the first issue was very straight forward but again I just could not seem to put aside the time. I got out my label machine and labeled the cables and also wrote out on a document what goes where. There has been some very frustrating times with my Elecraft kX3 trying the digital modes and it's not working. After checking everything (and I mean EVERYTHING) I simply plugged one of the interfacing cables into the wrong jack on the KX3.

Starting the labeling

To deal with the 2nd issue I now have a document going over the settings and common problems I have had and the fix for them. One issue I have had in the past was with Fldigi, I start the program up and hit transmit to check my ALC level. Instead of getting a solid 4 bars the ALC is pulsing from 2 bars to 5 bars. The simple fix (when I remembered) is for some reason my transmit is on the edge of the digi mode band. This causes the funky ALC reading. The fix is to just move your transmit to more centre on the band and your good to go.
Ah yes the 3rd issue....the comport circus! I have found that software does have a mind of it's own and I have had on occasion comports get changed around. So now I have a master list of what comport is for what software.
Finally number 4.......for rig control software I use Win4k3suite and you have available up to 4 virtual comports. Thats fine if you only have 4 programs you would like to use along side Win4k3suite. As for me I have a few more than just 4 programs mind you Im not using them all at the same time but you have to be aware to not run 2 programs that share the same virtual comports.....or.....things will just not work. To help me out I made a list of what programs and their virtual comports.

Mike Weir, VE9KK, is a regular contributor to AmateurRadio.com and writes from New Brunswick, Canada. Contact him at [email protected].

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Local Lightwave Activity / A New 630m Resource Site

28 March 2016 | by Steve VE7SL | Leave a Comment (0)

Toby, VE7CNF, has sent me some mail indicating that his new lightwave system is ready for a two-way test!

His system is very similar to the ones built and deployed by myself and Markus, VE7CA, in late 2013. The culmination of that activity is described here, in 'On Making Nanowaves - Part 6'. Our lightwave QSO and homebrew gear were later described in a 'how to' article in the 'The Canadian Amateur' as well as in the newest edition of 'The Radio Amateur's Handbook' (2016).

Toby describes his most recent pre-QSO backyard testing:

The lightwave gear appears to be working well. Focus looks good and the
finder scopes are doing their job. There's a reflective sign high up on a
hydro tower 170 meters away that's handy for testing. It lights up bright
when the transmitter's on it.

Back scatter off the clouds above my house worked too. I heard my CW beacon, audible 339, off a patch on the clouds about 1 degree wide. I don't really know if it was clear air scatter from closer by, or scatter off the clouds, but the spot was small. That's with the tx on the front deck, and rx in the back.

I used Spectran to check the noise from city lights in my area. At QRSS10
speed there are spectral lines at 540, 600, and 660 Hz. They aren't too
strong, but those are some frequencies we should avoid.

VE7CNF's lightwave system - TX (L) & RX (R)

As well, Mark, VA7MM, is also putting together a similar system to join the fun ... it's great to see new local activity!

Hopefully the weather will co-operate enough to allow us to make a two-way QSO later this week. Plans call for Toby to set up near the same location in West Vancouver used by VE7CA as it offers a clear LOS path to Mayne Island, 54km to the southwest.

54km Georgia Strait crossing (courtesy: https://www.google.ca/maps)

*****************************************************

Rik, ON7YD, has set up a new website devoted to information specific to 630m. His 472kHz.org site looks as if it will be a valuable resource for those looking to get information and a start on our new band. At present, there is some really great information regarding transmitters, antenna systems and calculating E(I)RP levels. Have a look!

Steve McDonald, VE7SL, is a regular contributor to AmateurRadio.com and writes from British Columbia, Canada. Contact him at [email protected].

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Portable Ops 10/45: Nice Lunch on the Radio!

28 March 2016 | by Burke NØHYD | Leave a Comment (0)

Wow, today was the most fun I have had in a while on the radio – the bands seemed decent today. So with my freshly charged KX3, and beautiful spring weather I set about to make some contacts from the local park.

N8XI (15024T) – Rick was calling CQ on 20 meters looking for SKCC members. I gave him a call and we had a quick exchange from KS to MI.

Then I started calling CQ….

KF8DA – Roger gave me a call from Ohio and QSB was really bad on his end, but we got the contact done.

NX3Z/QRP – Jim answered my CQ and was right down there in the noise most of the time. He was QRP from Arizona using a KX1 – it took many repeats but we finally were able to finish the QSO. Jim emailed me and said that even though he is an SKCC member he was using the keyer on the KX1 so this won’t count for an SKCC contact – but I always love 2xQRP contacts! Thanks Jim!

K7EP (1683T) – Art answered my call from Washington state with a nice signal and a nice fist.

WH6LE (13533S) – Last up for the day was Pete from North Carolina for a nice quick contact.

It was a fun day today – much better band conditions than last week. Thanks to everyone the found me! I did go up to 15 meters right at the end and called CQ a couple times with no takers.

I also made some SKCC contacts over the weekend, so right now I am sitting at 27 SKCC contacts as I work towards 100 for the Centurion award.

Burke Jones, NØHYD, is a regular contributor to AmateurRadio.com and writes from Kansas, USA. Contact him at [email protected].

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Portable Ops 10/45: Nice Lunch on the Radio!

28 March 2016 | by Burke NØHYD | Leave a Comment (0)

N8XI (15024T) – Rick was calling CQ on 20 meters looking for SKCC members. I gave him a call and we had a quick exchange from KS to MI.

Then I started calling CQ….

KF8DA – Roger gave me a call from Ohio and QSB was really bad on his end, but we got the contact done.

K7EP (1683T) – Art answered my call from Washington state with a nice signal and a nice fist.

WH6LE (13533S) – Last up for the day was Pete from North Carolina for a nice quick contact.

It was a fun day today – much better band conditions than last week. Thanks to everyone the found me! I did go up to 15 meters right at the end and called CQ a couple times with no takers.

I also made some SKCC contacts over the weekend, so right now I am sitting at 27 SKCC contacts as I work towards 100 for the Centurion award.

Burke Jones, NØHYD, is a regular contributor to AmateurRadio.com and writes from Kansas, USA. Contact him at [email protected].

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Weekly Propagation Summary – 2016 Mar 28 16:10 UTC

28 March 2016 | by Tomas NW7US | Leave a Comment (0)

Here is this week’s space weather and geophysical report, issued 2016 Mar 28 0122 UTC.

Highlights of Solar and Geomagnetic Activity 21 – 27 March 2016

Solar activity was at predominately very low levels with an isolated C1 x-ray event observed on 23/0354 UTC from Region 2524 (N15, L=277, class/area Eho/340 on 19 Mar). No Earth-directed coronal mass ejections were observed in coronagraph imagery.

No proton events were observed at geosynchronous orbit.

The greater than 2 MeV electron flux at geosynchronous orbit was at normal levels on 23 March, high levels on 22 March and moderate levels on 21 and 24-27 March.

Geomagnetic field activity ranged from quiet to unsettled levels with an isolated active interval observed early on 23 March. The period began with quiet conditions, but increased to quiet to unsettled levels late on 21 March due to the onset of a weak, positive polarity coronal hole high speed stream (CH HSS). Predominately quiet to unsettled conditions persisted through early on 24 March under the influence of the positive poarity CH HSS. Wind speeds averaged about 425 km/s through midday on 23 March. A gradual increase was then observed to a peak of near 565 km/s early on 25 March before decreasing to about 350 km/s late on 26 March. From 21-25 March, total field (Bt) ranged between 1-10 nT while the Bz component varied between +9 nT to -5 nT.

Quiet conditions persisted from late on the 25th through 26 March. Predominately unsettled levels were observed on 27 March due to the onset of a co-rotating interaction region in advance of another positive polarity CH HSS. On 27 March, wind speeds increased to near 440 km/s, Bt reached a maximum value of 12 nT while the Bz component rotated between +8 nT to -9 nT.

Forecast of Solar and Geomagnetic Activity 28 March – 23 April 2016

Solar activity is expected to be at very low levels with a slight chance for C-class flares through the outlook period.

No proton events are expected at geosynchronous orbit.

The greater than 2 MeV electron flux at geosynchronous orbit is expected to be at moderate levels on 28 March and on 01-03, 07-11 and 17-23 April. High levels are expected on 29-31 March, 04-06 and 12-16 April.

Geomagnetic field activity is expected to be reach G1 (Minor) storm levels on 02-03 and 11-13 April with G2 (Moderate) storm levels expected on 02 and 11 April due to the influence of recurrent, negative polarity CH HSSs. Quiet to unsettled levels are expected on 28-29 March, 04, 08, 14 and 23 April, with isolated active levels expected on 28 March and 23 April, all due to various CH HSSs. Mostly quiet condtions are expected for the remainder of the outlook period.

Don’t forget to visit our live space weather and radio propagation web site, at: http://SunSpotWatch.com/

Live Aurora mapping is at http://aurora.sunspotwatch.com/

If you are on Twitter, please follow these two users: + https://Twitter.com/NW7US + https://Twitter.com/hfradiospacewx

Get the space weather and radio propagation self-study course, today. Visit http://nw7us.us/swc for the latest sale and for more information!

Check out the stunning view of our Sun in action, as seen during the last five years with the Solar Dynamics Observatory (SDO): https://www.youtube.com/watch?v=zXN-MdoGM9g

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