Archive for the ‘radio’ category

Antenna work, completed and coming

May 8th, 2008

PL-259

I took K9BF’s TA-33jr down a few weeks ago because it didn’t look too secure and I wasn’t able to get it up high enough to play well on 20. I had entertained the thought of building an East/West-firing lazy-H array to replace it. But, that would have required me to move my high 40-meter dipole, probably the best antenna I’ve ever had for that band. I decided instead to build a Moxon, which seemed to be a fitting tribute to W4RNL, who recently became an SK.  The Moxon has about the same gain (albeit in one direction) over ground as the lazy-H and a little fatter beam.  It’s not yet operational; but, I’m working on it.

The 160-meter matching portion of the 80-meter dipole needs to be adjusted and repaired.  I didn’t use big enough RF chokes in the switching network and they got burnt.

I might do something to the southeast if I like the performance of the Moxon, too.  Hopefully, the beams will give me the edge I need to make some more QSOs on 20 in the Sprint and SS this Fall.

Grad school is really sapping my energy.  We’ve been on the road a lot and the end is not yet in sight!  Plus, there’s real work to be done, too.

Bench Time: Airplane and a TS-930 repaired

April 23rd, 2008

Benchtime

As I lamented in the last post, I am surrounded by ailing gadgets in need of repair.  Last weekend, I tackled two of them.  The first was the airplane.  A gust of wind had destabilized the plane sending it crashing to the ground.  The front set of pegs where rubber bands attach the wing were sheared-off.  A trip to a craft store with Sarah yielded an “1/8-inch” dowel and a sack of miniature thread spools.  I reamed-out two of the spools and press-fit them to the dowel for a slick replacement (sorry, no photo).  I have not flown the plane again, yet.  However, the weather has changed favorably.  So, that should happen any day now.

My older TS-930S developed a PLL unlock error over time.  The error occurred when I changed bands or modes.  Fortunately, several months ago, the topic had been discussed on the TS-930/TS-940 reflector, although I was just getting around to thinking about it.  Clif Holland, KA5IPF, who has repaired Kenwood radios for many years, suggested that a common culprit is the 36.1-MHz heterodyne oscillator in the signal unit and prescribed a simple adjustment of L77.  It took a little while to adjust it to my satisfaction.  Indeed, I wasn’t even sure I’d made any improvement at all at first.  However, once the radio warms up, band and mode changes are seamless again!  This sure helped out for fast QSYs in the Michigan QSO Party.

On the topic of TS-930’s, I’m still having woes on SSB with the other radio.  I swiped (and promptly returned) a microphone from the TS-850S at W9YH to ensure that the problem wasn’t my Pro-Set.  It has to be something between the mic jack and the signal unit.  But, the mic jack is a real pain to get to.  Someday.

Repairs and junk…

April 13th, 2008

One of the curses of attempting (I say ‘attempting’ because I’m mostly a failure) to be a “sustainable consumer” of electronics and appliances is the inevitable repairs.  My venerable desktop PC of 8.5 years (known affectionately by it’s hostname “sakhalin”) is finally showing its age.  It has trouble finding the boot drive from time to time.  The “A radio” TS-930S doesn’t transmit on SSB anymore (this is a long-standing problem I have yet to diagnose), which is unfortunate because it has the roofing filter and Inrad SSB filters.  The power nozzle for our Hoover canister vacuum cleaner needs an agitator belt.  I need to find a local vacuum repair shop because none of the big stores carry the right size.  I think Sarah would be just as happy to replace it with an upright.  But, the canister still works!  I wrecked the airplane a couple of weeks ago when the weather was not quite nice enough to be flying it.  Fortunately, I have $3 worth of MacGuyver parts and epoxy that should be sufficient to make that repair.  The wind broke one of the wires on my open-wire 80-meter dipole.  (Finally, I reached the point of “if it stayed up last winter it’s not big enough.”  The proof is in the performance, too.)

I’ll probably get the airplane and the antenna fixed yet this afternoon.  The other problems are more long-standing.  The desktop PC isn’t really necessary, especially since Sarah will be getting a laptop with her new job.  So, I really probably could let it go.  I still have the Pentium 166 that I bummed off of Dad for a contesting computer.  It’s working great.  But, do I unload the newer, superior computer that’s flaky?  I have been tempted to dump the 166.  I should try a new hard drive in sakhalin.  Then there’s Sarah’s desktop…I can count on one hand the number of times it’s been turned on since we got married and I was the one using it!  I’m holding onto Alan’s PowerBook because it’s the only place I have Adobe CS2.  And, I have the ThinkPad “contesting laptop” that Ryan gave me when I got married…  I guess if I weren’t such a tightwad and Mac-addict, I wouldn’t have this problem!  No more junk!

We have five CRT’s in the house…two Dell 19″ Trinitrons on my desk, Sarah’s 17″ un-Trinitron Dell, my oscilloscope, and the TV.  I’m not planning to replace the ‘scope or the TV anytime soon.  So, I guess it’s the computers are the ones that will have to go…I just can’t let go of my junk…  And, I went out and bought a new camera…sigh.

Cluster Crabs

March 24th, 2008

KH2D used to have a wall of shame called “Cluster Crabs” for all of the greatest abusers of the DX cluster network.  A tribute…

I shouldn’t get bent out of shape over what happens on the DX cluster.  But, I’ve been keeping an eye on it of late to catch 5T5DC when I can.  (I’ve got them on 40 and 80 now…hopefully.)  I could complain about the idiots who self-spot or treat the “Announce” feature like their own private chat room.  But no, this one goes out to the General class hams in the U.S. who feel entitled to have the rare DX listen in their part of the band.  I have seen this twice in the past hour!  Yeah, I know that the U.S. incentive licensing structure is an anachronism.  Seriously, if it’s that important to you, take one more written exam and you could have the run of the bands!  You should know half the stuff on the Extra from being a ham after a few years anyway.

That said, there is one eminent CW operator who has been licensed as a General for many years and it hasn’t hindered him one bit!

JGR and NCJ

February 29th, 2008

This week has been a banner week in the publication department.  On Tuesday, we got the proof of our paper “Optical observations of the growth and day-to-day variability of equatorial plasma bubbles” back from Journal of Geophysical Research.  On Thursday, I completed the final draft of “A multi-instrument technique for localization of equatorial ionospheric scintillations” which will go either to JGR or Radio Science on Monday.  And, also on Thursday, the National Contest Journal showed up with my article on bandpass filters and switching.

Unfortunately, I’m not completely happy with the NCJ article from a variety of standpoints.  I don’t believe it represents my best work, and I tried to cover too much too quickly.  I’m not really an expert on filters, either, just a cheap ham (that is, poor grad student) trying to do SO2R on a budget.  Perhaps I should have taken that tact.  Live and learn.  On the bright side, Zack Lau, W1VT, sent me a couple of QEX articles he’s written on filters for in-band operation.  I’ll have to look into those.  I hope to put an errata/bonus material page for the article on the filters part of the site.

Back to the grind of crunching numbers so I can write about them…I guess that outlook sounds bleaker than it really is!

TLF on the Mac

February 24th, 2008

Last Sunday night, I hacked PA0R’s TLF Linux contest logging software to build on the Mac.  I tried it once before without much luck.  But, this time it seemed work much better.  If anyone is interested in a REAL contest logging package for the Mac, this might be it.  I’m going to try to get it going with a WKUSB at some point.  If you’re interested, shoot me a note.

The Golden Log and more…

February 24th, 2008

N6TR posted the preliminary CW Sprint results earlier in the week.  I was hoping for top-10 low power; but, ZF2BJ surprised and bumped me out.  However, the really good news is the Golden Log (no copying errors)!  This is my second golden log in a Sprint; the first was during the LP Sprint in April 2006.  I’m pretty happy with my result because it’s within 20 QSOs of KA9FOX (my closest geographic competitor in the top-10) who has a 100-ft tower with 2-el on 20 and 40.

Scott kicked my butt on 80 and 20.  I’ve got about the best domestic 80-meter antenna I can squeeze onto my lot right now.  I’m thinking of replacing the TA-33jr at 18 feet with a little more firepower on 20.  I’m not sure exactly what, yet, though.  I really am looking forward to putting the KT-34XA stack that’s piled next to my folks’ garage up (they won’t mind that one bit, either).  But, first things first.

I skipped Sunday School this morning to spend some time with cocoaNEC on my MacBook.  (Why go when I’m going to be dreaming about antennas the whole time, anyway?)  This is some pretty sweet software.  It really lets you manipulate the NEC internals all the while having an EZNEC-style interface for entering wires.  It’s a lot better than 4nec2.  I’ve been thinking a lot about building a lazy-H (two horizontal collinears stacked vertically) that fires East-West.  But, I just don’t quite have the height.  This antenna would also be an awesome cloud-burner on 40, although, I hope we move before we get enough sunspots back to really have fun with that.

My biggest problem is working adjacent states on backscatter…I can always hear W9RE and N9CK on 20; but, they can never hear me.  I think that the lazy-H would work well for that.  My second problem is to be loud enough if we get an Es opening into New England, Texas, or the Southeast.  I’ve thought about building a 20-meter 4-square on the roof.  But, the material cost is relatively high given the performance.  I can’t lay down enough radials to do a parasitic vertical array.

Who knows if any of this will actually happen…  I just finally cleaned-up the shack today after months of squalor.  It was even a heap for the Sprint, as much as I prefer to have things cleaned up for contests.  The buro cards are starting log-jam again.  I need to run some more CE/K8GU cards.  Speaking of being DX, I’ll be on Crete for a conference during WPX CW.  Still haven’t decided whether to bring a radio or not.  Sarah might not be too happy if I spent a lot of time at the conference and on the radio…although, SV9/K8GU is tempting especially because Greece is a CEPT country and there’s no licensing hoopla…  I’d just bring an antenna for one band…probably 20…  The DK9SQ mast is a little too big to schlep along…I’ll see how packing goes…

Ham Web vs. Ham Radio

February 11th, 2008

It seems that there are a lot of people on the Web who like to talk about ham radio.  How many of these people actually talk on the radio?  New challenge: operate more than I spend time on the Web doing ham radio stuff.

Sprint and SO2R thoughts

February 3rd, 2008

The CW Sprint is one of the best contests going. It’s also the first contest that I ever tried operating SO2R a couple of years ago. After last night’s Sprint, I’ve decided that one of the greatest secrets of learning SO2R operation is knowing when NOT to use it. And they say it’s a bolt-on advantage…

Summary:
Band QSOs Op Time
---------------------
80: 98
40: 93
20: 29
---------------------
Total: 220 Mults = 41 Total Score = 9,020

This was my first effort over 200 QSO’s. I’m already shooting for 250 the next time. I really need to get my mobility up! I’m never quite sure whether my poor performance on 20 is due to the lack of a good antenna there or lack of propagation. Maybe a little of both. I do keep thinking of putting up a lazy-H. But, then, I’d have to move the 40-meter dipole that has performed so well.

I never heard WV or NV, which is unusual.  I did hear K5RC calling in the FOC Marathon.  I was tempted to see if I could talk him into a Sprint QSO…but, I decided against it.  I was using the TS-930 he sold me on 40 meters, though!  I read VE6EX’s post on 3830 that he had S9+30 noise on 80!  I called him for over a minute near the end of the contest before K5KA swooped in and got him.   I heard him and VE6CNU on 40; but, was always out-of-sync.  I heard K4FXN (KY) on 40, also…welcome to low-power, low-antenna, contesting.

Goals for next time:  250 QSOs, better multiplier total.

NAQP and LoTW

January 16th, 2008

I entered the North American QSO Party CW Contest somewhat seriously for only the second time last Saturday.  I’m pretty happy with the results, especially considering that this score is 50% higher than my claimed score the last time.  I ended up with only 9.5 hours due to the 160 antenna situation.

Summary:
Band QSOs Mults
-------------------
160: 33 20
80: 279 47
40: 261 51
20: 66 29
15: 17 5
10: 1 1
-------------------
Total: 657 153 Total Score = 100,521

Ten and fifteen meters stunk…no big surprise here for this part of the solar cycle.  Although, I would liked to have done better on fifteen.  I took my off times (an hour each time) during the second and sixth hours of the contest.  I don’t know if I would do it that way again;  I had a really good run on 40 during the day.  I tried to work the second radio then; but, I haven’t mastered that, yet.  The first hour had the worst (< 60) rate.  I did much better after that.  My totals on 40 and 80 are within striking distance of the big guys like W9RE.  But, I just don’t have the firepower on the high bands nor the ears on 160 to do well there.  Of course, there’s still the whole skill problem, too…

Topband was a disappointment…I was hoping for about 40 multipliers and 100 QSOs.  I hauled an MFJ tuner up on the roof late in the contest to load-up the 80-meter dipole and feeder against a single elevated radial on 160 since I still don’t have that automated.  That could be a tonight project.  The noise on 160 on the vertical was 10-15 dB over S9.  Those 33 contacts were fought hard by me.  I need some RX antennas.  I talked to K9AN yesterday.  He suggested a K9AY loop.  I’m thinking about active verticals with a variable phasing combiner…less footprint.  We talked about pre-amps.  He wants to measure the NF of whatever I come up with out of J310’s from my junk box.

I requested a new LoTW certificate this morning since mine expired in January 2006.  Hehe…oops.  They protect your QSO integrity like Fort Knox!  In fact, they probably have a better idea of who you are than most credit bureaus.  I need to go through my logs tonight and clean everything up to get ready.  It sure beats QSLing, though…  I’m sure I’ll make a bunch of people happy in a few weeks.

Also came up with a great SDR idea yesterday that could be my new secret weapon.  It should be pretty easy to do, too.  No more on that until I get one working…