This would be my first trip running the FTM-350 with APRS. I spent most of my day Saturday, prepping the Durango… getting the Yaesu wired and configured, and getting the Sirius satellite antenna and receiver mounted. It was all well worth the effort. It was a joy to listen to JamOn for most of the trip, driving to Phish, moe, and Umphrey’s McGee to name a few!

We arrived in Dayton at 6:30AM. We called during the night to check on room availability. We were excited to find out that our room was empty and we could check-in early. Big Kudos to the Hawthorne Suites and staff. This is my third Hamvention staying at this location, and I have always been extremely satisfied with the accommodations and service. I hate giving away this secret as it always a great deal… a huge two bedroom penthouse suite, free wifi, continental breakfast, and priced right. It is a bit further from Hara Arena then some other accommodations, but I like the location.

As soon as we got in the room, I unpacked, whipped out the Macbook and checked aprs.fi to see how well we tracked. I was pleasantly surprised with a really quality set of packets, considering the desolate areas of western PA that we had traversed.

APRS20120516

It’s time for a nap. I will be video taping and blogging during my entire trip, so check back for updates.

One of the neat things with Software Defined Radio (SDR) technology is that it seems to be reducing the expense for someone to get a really good receiver..  I’ve touched a few of the really high end radios at Hamvention… but I doubt that a $10,000+ rig is in my near-future radio budget.  Part of of my reason for starting this website and posting my shack design and progress, is to highlight the ability of a radio operator to make some incremental additions, and to work towards a reasonably high quality HF station. 

If you’ve read my recent posts about my first contest experience, this interface was inspired by my difficulties with transmit/receive switching.  I found a a really good site by WS4E about interfacing an FT-450 to a Softrock.  Most of the basis of this project is based upon the work that he had already done.

The idea is to tap an internal point in the radio that is after the bandpass filters and before the initial IF stages.  This will allow an external SDR receiver to connect to the same antenna as your transceiver.  The tap point is already after the internal T/R relay, so there is no requirement for additional switching.  In fact, the neat thing is that the transceiver and SDR reciever can tune different frequencies simultaneously using the same antenna with this upgrade.  The one caveat is that the tap point being after bandpass filtering, your external SDR will be limited to using the same operating band as your transceiver.  I don’t consider that to be a limitation, as this fits the way that I plan to use this configuration.

After reading the WS4E post, I made contact with Jack, K8ZOA, of Clifton Laboratories.  I ordered two of his Z10000U amplifiers.  I mentioned to Jack where I had found his amplifiers and what I was hoping to do.  I originally wanted to get the assembled boards in external boxes, as was done on the WS4E site.  Jack mentioned that he had a customer mounting the buffer amp internally in an FT-450 and said that it would be advantageous to minimize the legnth of cable from the tap point to the buffer.  I took his advice.  He provided the buffer, an SMA with attached cable, and an SMA to BNC cable.

First step is to get power for the buffer.  The simplest place to get the power was at the input location of power on the top of the radio.  There were two small pads right below the large input cables that made for a convenient attachment point.  The cable was easy to route from the top of the radio to the bottom where the buffer would be located.  There is a hole to provide access to the coax feed from the upper board to the antenna tuner.  In the picture it is difficult to see the black lead.  The pad layout is symmetrical.  It is also possible to just use the connection of the ground stud on the buffer to provide ground, but I provided a positive and ground, in case I had mounting issues.

The next process was to mount the SMA.  There is plenty of space in the back and bottom of the radio for the cable and the connector.  The one thing that was problematic, was the length of the SMA connector.  The aluminum cast housing of the radio was thick enough that I needed to remove the lock-washer and star-washer to allow sufficient length to connect to the external cable.

There was a perfect place to mount the buffer, by using a small metal stand-off.  The Z10000U buffer am has a single mounting hole.  It doesn’t need anymore as it is a really small board.  The standoff was one from parts box that was a leftover from taking old pc’s apart.  In the pic, you will also notice that there is another standoff on top of the board.  Two reasons:  I figured it would provide a small support to prevent the bottom of the case making contact with the board, and the other reason was that I couldn’t find the right size screw to fit the standoff.

After re-assembling the case, I was very happy to find that the FT-450 still worked as it had before my modifications.  One of my colleagues actually asked my why I would mod a modern rig like this.  I quickly exclaimed that I had purchased the radio used.  If it was a brand new rig, with a brand new price tag, I would have been more hesitant to try this.  I connected the SDR-IQ to the new SMA connection and it worked as I had hoped.  I found an empty frequency, and tuned up.  It was easy to see that the T/R switching was working as I had hoped, as the waterfall went blank except for my transmission.  I will still need a function to mute the output of the SDR software, as the SDR receiver is still sensitive enough to pickup the local transmitted signal.  The good news is that there is no overload of the SDR receiver.  I may still consider building a receiver guard type protector for SDR, but even at a full 100 watt output from the FT-450 there was no overload indicator on the SDR-IQ.   The performance of the SDR-IQ was so good to start, that it is hard to tell if the addition of the FT-450′s bandpass filters contributes to even better performance.  I have a fairly high powered AM station nearby and I would think that receive performance could only be improved by tapping after the bandpass filters.

Continuing from my first post about contesting, the feedback coming from my speakers is due to the SDR receiving my locally transmitted signal.  I need to mute the audio out to the speakers during transmit.  I could fabricate some relay driven device to switch the PC’s audio path to ground during transmit, but I really would like a faster solution.

HDSDR makes reference to a TX function, but wants two sound cards to route mic inputs and speaker outputs…  and it doesn’t seem easy to do.  I know SDR-Radio has the capability to sense when the transceiver is transmitting and it automatically will mute its output.  I needed to switch to SDR-Radio.  Bummer, as I really like the interface on HDSDR, and I am much faster at navigating with it.  Maybe I just need to learn to use SDR-Radio better, but for now, N1MM is enough for me to handle.

After finally, working out the software kinks, I ended up settling on SDR-Radio and N1MM.  It was a bit after 1PM and the contest was already underway. The activity in mid-afternoon was on 10-meters.  Interestingly, one of my first contacts was a Costa Rica QSO.  Having only one antenna, a 80m off center fed dipole, and only being 24-feet above ground, I was going into this experience with low expectations.  I was pleasantly surprised to be able to work just about every station I called.

The NCJ NAQP is a great contest for a beginner.  First, the maximum power is limited to 150 watts.  This lets someone like me, without a big amp, to get in on the action.  Another thing that made this a good contest for the novice, is the simple exchange, being just name and state. Another nice thing with this event, is that it is a 6 hour run, so it is not a long marathon of 48 hours like some of the other events.

I was racking up the Q’s, and things were going well… and then SDR-Radio crashed.  I think I may have actually missed logging one of my contacts, because I think I had finished the exchange but didn’t commit the log.  If you are a station that is missing in my log, my apologies…  With the Virtual Serial Port Emualtor (VSPE) linking the radio to N1MM and to Omni-Rig via SDR-Radio, I think that VSPE lost contact with the radio.  Then N1MM could no longer pool the radio.  Then N1MM completely hung.  If you are reading this, certainly don’t blame the software, as that I am sure my setup (or the operator) is at fault.  It did take a full reboot to get things back up and running.

I ran sporadically throughout the afternoon and into the early evening.  My wife joined me in the radio room to see what I was doing, and observed for over an hour.  I am hoping she will be interested in operating during some of the RTTY and PSK events (she’s not excited about talking on the mic)!  In the end, I made 97 Q’s with a score of 4,000+.  I made contact with just about every station that I called (I can only recall two or three that I passed).  The contacts from New England to Florida,California, Texas, Washington, Hawaii, and the Virgin Islands boosted my confidence in my antenna and radio operation.

As a post-event evaluation, there here are a few key points:

1. Be prepared.  Test your equipment, software, computers, antennas, etc.
2. Take the time to learn your software before contesting.  Know the features and functions and how to find them.
3. It may be advantageous to operate on the days leading up to the contest, as to test your equipment and to evaluate propagation.
4. Do your best and always strive to improve your operating skills.
5. If you are going to make a serious run at any of the contests, you need to be well rested and focused.

Check back and check out our progress.  Lots of upcoming shack improvements on the to-do list.

I had hoped to be able to have a colleague over to join me in attempting this run at the NAQP SSB contest.  Unfortunately, the week had some crazy turns and things didn’t work out so well.  I had to postpone the invite.  I wasn’t going to be able to spend the day focused on operating and I didn’t want to waste the long drive for someone else.  Add to the mess, our first winter snow, as just one more thing to disrupt my day.

I decided that I would try N1MM for logging, based upon the recommendations of Dave, NB3R.  He is in avid contester and I greatly appreciate the knowledge he has already shared, and look forward to spend some more time learning from him.   The N1MM software system is quite intense and has a ton of features.   That also makes it a bit…  well, lets just say it isn’t completely easy.  I did manage to get it setup and configured.  But that was just the first step.

Of course, my setup isn’t exactly easy.  I have been experimenting with the use of an SDR-IQ for receive coupled with my FT-450 for transmit.  The receive on the SDR is absolutely amazing.  I have been able to get HDSDR and SDR-Radio working with SDR and to simultaneously tune the FT-450.   The thing I hadn’t actually done is really transmit.  Up to today, I just had the 450 patched into a dummy load…  and with good reason.

The SDR has a great receiver, which also means a sensitive front-end.  It really should have additional protection when operating in close proximity to a transmitter.  And there are some great commercial solutions.  However, none seem to be available.  In Europe there is an excellent product called an Elad Switchbox which automatically switches your antenna from your transmitter to your receiver.  It uses RF sense or can be triggered from the transmitter.  Great; except I have been unable to find one in the US and several attempts at emailing the manufacturer have yielded no replies.    For a simple protection for receive-only, there is unit called a DEO ReceiverGuard.  I would need to have the unit patched between the antenna and SDR, and since it doesn’t have switching I would need to use a receive-only antenna.  Not a great idea either. And to further complicate things, the DEO uses a small lamp to shunt away excess voltages to ground. If the protection exceeds a certain level the lamp filament breaks like a fuse. GREAT, except that no supplier seems to have replacement lamps.

My solution, attempt to build a device that wraps together the best of the two units; Transmit/Receive switching and receive protection.   I found a schematic for the receiver protection circuitry and they also use a different type of lamp that is more readily available (I ordered 20, just to be sure).  I consulted with Eric, AI3D on the T/R switching and he guided me towards some relays that were adequate that were already in my parts bin.  The relays switch the antenna feed line between the transmitter and receiver.  Additionally the receiver gets switched to ground when the transmitter is connected and transmitting.  At this point, some of you that may be following along may wonder why I need the protection circuit if it is already switched to ground when the the transmitter is connected.  Good question!  The reason is, that I am already planning for the likely possibility of having another operator and another station active in the future.  So, the protection is there for the SDR in case another operator transmits in close proximity to the SDR.

I had drawn up a schematic a few weeks ago, and ordered parts.  My plan was to build this the week before the contest.  Like I said before, the week, just was a mess, and that never happened.  So, the way to start my first contest.  Throw caution to the wind, try using an untested software configuration on my pc for logging and try and whip a completely custom circuit for wiring together the transceiver and receiver.

I mocked up the relays and component on a proto-board.  Soldered them all in place and tested the switching with my bench supply.  All seemed to work well.  Now, time to hook it to the radio.  Oops.  The plan was to trigger this from the linear keying on the FT-450.  It would switch the relay instead of switching an amp. No problem, except the 450 uses a rare 10-pin mini-din for that hookup, and I don’t have one.  On to plan B.  I’ll use the foot-switch I was planning on wiring up for PTT, to trigger the T/R relay, and add an opto-isolator tapped off the foot-switch to trigger PTT.  Add a few resistors, 4N33 and diode to the board, test it… everything works.  Grab the nice aluminum box I bought to hold the board, go to the connector box to get some SO239′s, and there is only one there.  Ouch.  Forgot we used them to make some center connectors for dipoles.  Now I can’t finish the box, because I don’t have enough connectors.  I thought about swiping them off the dipole adapters, but I think I made a better choose to just use some old PL239/RG8 pigtails and really do an ‘ugly’ prototype.  Soldered the cables for the feed line and transceiver hookup, hacked up and RG58/BNC cable for the receiver output.. and Voila.  ready to go.

I hooked a power line to my foot-switch, patched the transceiver and receiver, and hooked the output line to a dummy load.  I set the power to 5-watts, pressed the pedal and the PTT circuit worked.  Cranked up the power slowly to make sure the SDR wouldn’t get overloaded… no problem.  The grounded input lead seems to take care of it.  It still picks up the transmitter but at a level that doesn’t light the overload indicator.

Now that the switchbox is working, it’s time to get back to N1MM.  I had downloaded and updated according to Dave’s instruction. Configure my personal data.  Downloaded updated master call table.  Setup a new log for the event.  Made a quick test entry.  No problem… except the frequency isn’t correct.  Forgot to setup the radio.  Went to the config panel to put in the radio config…. Can’t do it.  Serial port is already in use.  The HDSDR uses Omnirig to talk to the radio to sync the SDR and transceiver.  Ok, I know how to fix this.  VSPE to the rescue.  Add a quick virtual serial port splitter, do some Com port reassignment in all the software configuration.  Test it.  It works.  HDSDR talks to the FT-450. N1MM polls the Ft-450 for the correct frequency.  All is well in the shack.

Take a quick break.  Get some lunch.  Contest is about to begin.  I had hoped to get a bit of time to tune around, but it is already after 1 and the contest is rolling.  Quick patch the antenna to the switch box.  Start tuning and see, everything is up on 10M.  Hit the TUNE button on the 450.  ERROR.  Oh crap, the radio can’t tune if the antenna isn’t connected.  The only way to connect the antenna is to press the foot-switch, trigger the relay… but that engages the PTT and you can’t tune with the PTT engaged.  Quick.  Think.  Ok, disconnect the mic input.  Press the foot-switch, the antennae relay will switch, but the PTT isn’t hooked into the radio, and I can press the tune button, and tune to the band.  Works.  And fortunately for me, my 80M OCF is really good on 10 and won’t require much re-tuning.  Back to the action.  Plug the mic line back in, ready to go.

Find a station.  Enter his call in the logging window.  Hit the foot-switch, and before I even get the first letter of my call out, this awful feedback starts coming out my monitor speaker.  Remember that part where I told you about the SDR still picking up the transmitter, even though its antenna line is switched to ground.  Since it picks it up, my audio is feeding into the speakers while the mic line is open.

I’m going to take a break in telling this story.  I will put the next chapter up in the next few days.  Check back for the continuing saga of my first contest day!

I fired up Photoshop and started laying out a new card.  I was looking for some samples of other peoples cards.  Ironically, my google search turned up eqsl.cc.  I remembered I had an account there, so I looked up the password and logged in.  I was a bit surprised to have an Inbox of contacts waiting for replies.  Most were from from my recent run during the PA QSO Party.  I decided to whip up a design and upload it.  The above picture is the result.

Hopefully I will figure out how to get my logs uploaded and can start confirming the contacts in my Inbox.   If you are waiting on an eqsl from me… please be patient and it will be there soon!

KW3K Shack 2012/1/2

Like most, my shack always seems to be a “work-in-progress”.  With that in mind, I thought it would be worth posting some pics as time goes by; documenting the progress and projects.

Since a picture is worth a thousand words, the first step was to get a good image.  That became a project unto itself.  With several computer displays and LED lighting, it proved quite difficult to get an image that showed enough detail that everything could be seen easily.  Regardless of my exposure settings, either areas were washed out, or equipment was lost in the shadows.

Enter HDR (High Dynamic Range Photography).  This is a process of taking a series of several photographs at different exposure settings, and combining them via software.  I use Photoshop to combine the images.  The included image of the shack was comprised of 15 images taken using Breeze DLSR Remote Pro for Mac.  The Breeze software allows you to control your camera remotely from you computer, setting exposure and bracketing settings.  The software is extremely powerful and has a ton of features.  I highly recommend it, and have been using software from Breeze Systems for many years.

I had hoped to get more info posted about the shack, but the process of getting the picture took much more time than anticipated.  Check back for updated posts highlighting the equipmnet, projects and plans.

The goals for this site are to promote and educate.  I believe that Amateur Radio is an important means of communication, particularly in times of emergency.  In recent years, Amateur Radio licensees have been growing at a rapid pace, coinciding with a more prominent focus on emergency preparedness in today’s society.  Although obtaining an Amateur Radio license is a important first step, consistent operation and development of skill is critical to being ready to operate in times of need.