Friday, November 30, 2007

Don't overbid on eBay ham gear!

I just don't get it. What chemical imbalance does an auction trigger that makes folks over-bid?

Look at this auction:
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&rd=1&item=170172559350&ssPageName=STRK:MEWA:IT&ih=007

Ooo, aaahhh. It's a mint IC-706MKIIG with a DSP module and a remote kit and the MARS/CAP mod. It just sold for $900 big ones plus $25 shipping!

Now look here:
http://www.universal-radio.com/catalog/hamhf/3450.html

And here:
http://hamradio.com/cgi-bin/uncgi/ase?ITEM=ic-706&model=Model

These new radios also include the UT-106 because it's standard equipment on the IC-706mkIIG. They also include the remote kit because Icom is giving it away for free. They also have a $50 rebate bringing the price down to $900. So what does the eBay 706 have that the new ones don't? The MARS/CAP mod? This mod requires the removal of a diode. One stinkin' diode. The NEW radios come with Icom's factory warranty, which IMO is worth a lot more than the labor to remove one diode.

I guess some people just don't like to lose. Maybe I should buy a new IC-706mkIIG, perform the MARS/CAP mod, and sell it on eBay.

73 de N1YWB

Tuesday, November 27, 2007

ARRL/RAC Sections Quiz


Click here to take free online ARRL/RAC sections quiz

Some contests require you to log ARRL/RAC section abbreviations. This includes ARRL Field Day and Sweepstakes. Being able to enter those abbreviations quickly and accurately is critical to keeping your rate up and avoiding busted QSOs. But remembering all those abbreviations can be a pain. Most are the same as their state mailing abbreviation. But who can remember the abbreviation for Newfoundland-Labrador? Or Mississippi/Montana/Minnesota/Missouri/Maine?

Now you can easily memorize all the ARRL/RAC sections by using my handy dandy sections quiz program. It displays random section names and requires you to key in the correct abbreviation, and keeps track of your score.

The program is written in JavaScript embedded in the HTML on the web page. You can save the HTML file to your hard disk to practice offline. The code is free open source software so feel free to modify it. If you make useful modifications please send me the patch and I'll incorporate it into the program on my site.

Radio Shack HTX-10 Review

Introduction
The HTX-10 is a Radio Shack branded 10 meter amateur mobile transceiver. It's probably sold with the expectation that most buyers are CBers who want to run over the legal limit. I don't care as long as they stay out of the ham bands. I got mine about 5 years ago when it was on clearance for $50.

On the air
I installed it in my Oldsmobile Cutlass Supreme with a big open coil mag mount CB antenna that I trimmed for 10 meters. The sunspot cycle was peaking at the time, and I worked all over the darn world with that setup, Africa, Europe, Asia, South America, no problem.

Audio reports are OK. I've only operated it on SSB, so I can't comment on the FM or AM performance.

Now that we are at the bottom of the cycle, the radio is practically useless for long haul communications. It works fine for talking to locals, if there are any 10m locals in your area. If you do own one of these radios, hang on to it. It will be more valuable and more useful when the solar cycle picks up. If you don't own one, now is a good time to buy, but watch out for rip-offs on the greedbay. This radio sold for $50 new when it was on clearance.

Rants
The radio doesn't work if the microphone is disconnected. I discovered this by accident and assumed the radio was DOA. Not so, just a boneheaded design flaw.

The tuning using the main tuneing knob is quite course. You pretty much always have to fine tune with the RIT knob. This would be fine except some idiot also made the RIT knob the "push func" button that you have to hit to access the second function of the front panel buttons. WTF?? Whatever, nobody ever said it was a contest radio.

Summary
Likes
  • Cheap
  • 25watts
  • SSB, FM
  • Rig + cheap CB antenna + open band == work the world
Dislikes
  • No CW
  • AM for CBers and freebanders
  • Microphone must be connected for the radio to power on
  • Course tuning
  • Constant RIT adjustments
  • Idiotic "push func" button on RIT knob
This radio is nothing special, but for the price it's probably the cheapest way to put out a mobile HF signal. When you consider how cheap CB antennas are vs. multiband ham mobile ants, then the low total cost of the mobile station really becomes apparent. When the next solar cycle picks up, you can have a lot of fun working DX on it while driving around town.

Monday, November 26, 2007

MFJ 1786 Super Hi-Q Loop Antenna

They say the proof is in the pudding. So here it is.

In the 2005 IARU HF Championship, I operated this antenna and a 80m window-line fed dipole. Both antennas were up about 40' and horizontal. I put them on a switch so I could select whichever was stronger for the signal I was trying to copy. I would estimate that the loop was louder on about 50% of signals, even on 20m. Considering that the theoretical efficiency of the loop is quite a bit lower than the dipole on 20m, I attribute the fact that some signals were stronger on the loop to the fact that the 80m dipole has a very "lobey" radiation pattern when tuned to 20m, whereas the loop has an omnidirectional pattern.

The bandwidth of the antenna when tuned is quite narrow, especially on 20m. This requires frequent retuning. When calling CQ this is a non-issue. When searching and pouncing it is a little bit annoying, but once you get the hang of it you can practically tune it by ear by listening to noise or signal strength, and just tap the tune button as you tune up or down the band. Once you find a frequency to operate on it's easy enough to fine tune it while calling using the cross-needle watt meter. Having the extra work to do with your hand isn't ideal for contesting but if you are using this antenna in the first place it's probably because you are in a portable or antenna restricted situation.

Likes
  • Compact size
  • Works close to ground in vertical orientation
  • Covers 10m through 30m continuously
  • Tunes up quick and easy, especially for small freq changes
  • Can be pre-tuned based on signal strength
  • Narrow bandwidth acts like a pre-selector
  • Omnidirectional radiation pattern
  • Horizontal or vertical polarization depending on installation
  • Aluminum construction is light and strong
Dislikes
  • Requires frequent retuning, even for small freq changes, even for RX only
  • Changing installation height or proximity to metal objects requires fiddling with feeder coil
  • Inaccurate wattmeter
  • Lossy at lower frequencies
  • Must be used in vertical orientation if installed lower than 30' above ground
  • A copper loop would have been higher efficiency
I placed 6th in the Single Op Low Power W/VE category. So there's your pudding. You might not win the contest but you can place top 10. This antenna doesn't suck.

Yaesu VX-7R Review


Introduction

I've owned my VX-7R for about 3 years. I am not kind to my equipment, especially not my HTs. I have used it in tactical situations, and I have worked with others who use it in tactical situation.

Features

The best thing about this radio is the mechanical construction. The magnesium housing is extremely rugged. You could probably hammer nails with it. The paint is starting to flake off the edges which is ugly but doesn't really affect functionality. I love the fact that it's waterproof. I have no qualms about using this radio in any conditions on land or sea.

A lot of the "features" seem silly to me. I guess you might use the barometer. Icon editors, font
editors, who cares? You can't even really use them without buying the computer programming cable and software. Editing a font pixel by pixel on the radio would take you a year. It has a dedicated WIRES button. Does anybody even use WIRES? Does anybody operate 6m on an HT?

The belt clip is the flimsiest part of the radio. Mine broke. It still works but the top part snapped off. Not the part that screws on to the radio but the clip part. It's like one of those cell phone clips that you rotate the phone over to take it off. It's fine when you are standing up but impossible if you are sitting. I get in the habit of always taking the radio off my belt before entering a vehicle.

On the air

I get OK audio reports, good communications grade audio.
The lithium ion battery lasts a very long time. For all day operations you should still have a spare. The batteries are expensive and like all lithium cells need to be replaced every few years.

I was disappointed when I discovered that, while the VX-7R has dual receive, it is NOT full duplex. I was hoping to use it for satellite work, but it is not well suited for this. Being able to hear yourself on the bird is important for aiming your antenna and correcting for doppler shift. You can do it without full duplex, but it's more difficult and less reliable.

My biggest complaint about this radio, and I don't think I'm alone here, is that it is dang near impossible to program it. Punching in a frequency in the VFO is easy enough. Setting repeater shift and tone frequencies is not intuitive; it doesn't actually require that many button pushes but it's pretty different from other radios and nobody will figure it out without reading the manual first. I usually take a few tries to save a memory. If you use this radio for any tactical comms, I urge you to keep the manual in your go-kit. Also get a quick reference card, print one out online or make your own. People in tactical nets who can't program their radios are a serious problem, and I've been in nets with more than one VX-7R owner who didn't know how to program his radio and didn't have his manual. This seems to be indicative of Yaesu's current crop of radios.

Summary

Likes

  • Rugged, waterproof construction
  • Long battery life
  • Rugged, waterproof construction
  • Dual receive
  • Did I mention the rugged, waterproof construction?

Dislikes

  • Paint wearing off
  • Goofy, weak belt clip
  • Typical of dual (tri) band radios, the wide front end is susceptible to interference
  • Expensive batteries
  • Not full duplex
  • Incredibly difficult to program

HTs take a lot of abuse and this is the first HT I've owned that I haven't been afraid to abuse. I guess thats the most important thing about an HT to me. The warts are easy enough to overlook, as long as you are competent enough to remember how to program the basic stuff.

Yaesu FT-897 review

Introduction

When the FT-897 was announced, I was immediately drawn to it. I liked the way it looked, the impressive feature set, and the battery option. I have owned it for several years now, and used it at home, in the field, and in contests.

The FT-897 is a good looking radio. It features a distinctive design that is eye catching to technoweenies like me.

Features

I really like having all bands from 160m to 70cm (minus 1.25m, although does anybody really use that band?) I have a wide range of interests within ham radio, that span the complete RF spectrum. Being able to access all those bands and modes on one reasonably priced radio is a big plus for me. Yes it's a compromise, but it's what I can afford both in terms of dollars and space usage.

The size is useful for portable and space-limited base operations. The spinner knob is big and heavy, I like it fine. It's just too big to use mobile unless you have an 80's or earlier full size pickup. A remote head option would have been nice.

The battery option is useful for emergency field work. The radio can be up and running with little more than an antenna and tuner. Caveat empator, even at 5W and low duty cycle, the batteries last up to about 8 hours. This isn't a self-contained field day station. But the ability to get on the air quickly could be beneficial during emergencies, on the assumption that an additional source of power will be available later.

I purchased 2.5khz and 200hz collins filters, the former for SSB and the latter for CW and narrowband digital like PSK31. I know everybody likes “digital panoramic tuning” but when some horribly overdriven nearby psk31 signal blows away the one you're trying to copy, a narrow filter and semi-manual tuning are the way to go. The filters are as good as any Collins filter in just about any other synthesized radio on the market. It is certainly not as good as the filtering in the Elecraft or high-end TenTec rigs.

A built-in TTL level converter would be nice. Why do most manufacturers still insist on selling one as an overpriced accessory? Oh wait, I just answered my own question.

On the air

I've gotten several good audio reports with this radio. I took the time to fiddle with the DSP mic filtering a bit using a second receiver. I'm not an audiophile, I don't really care if I sound good, I care if they can copy me. But I won't complain about sounding good either.

The reciever is mediocre. I haven't honestly used it too much for weak signal VHF. On HF It's plenty sensitive, well above the noise floor. On HF it suffers from the usual overloading during crowded band conditions and strong stations a few Khz away. This is not a contest radio. That IMO is a big strike against it for emergency operations. What if the emergency takes place on Sweepstakes weekend? Truthfully not many radios on the market do much better. Again see Elecraft and TenTec with their superior receiver designs.

What really sucks about this radio is usability. First of all, the LCD display just sucks. It's horrible. It's tiny. It has a viewing angle of about 2 degrees. It is very low contrast. It changes color, but how useless is that when only one or two colors actually allow you to read the dang thing? I keep it on white or near-white to maximize viewing angle. I might actually find space to mount it in my Jeep except that unless it's pointed directly at my face I cannot read the display and having to crane my neck over while driving is just not acceptable. Did I mention the display is tiny?

The user interface also sucks. Too few buttons, too few knobs, too many menus and scrolling through multi-function button functions. There are three multifunction buttons that do just about everything you want to do frequently. When I operate this radio I spend about as much time scrolling through the various button functions as I do talking on the dang thing.

The information displayed on the screen is barely acceptable. My only major complaint about it is that it only has one meter. I demand a dedicated indication of what my power output is so I don't accidently blow 100w when I'm on battery or tuning up or something. You have to jump into the menus to check or set power, annoying. The meter will display power but only while you're actually transmitting.

While I'm at it, Yaesu seems to have trouble making useable radios these days. My VX-7R is very difficult to program and I'm a professional computer programmer and technophile, things like that aren't normally difficult for me. Also the FT-857 has a display that is actually even smaller than the FT-897, I can't imagine trying to read it while driving. My old Yaesu radios were all fine, my FT-1500 isn't too hard and my old FT-416 was dirt simple. I know radios have gotten more complicated, but Kenwood and Icom both seem to have managed somehow. Yaesu needs to wake up to the fact that their current crop of radios suck in the usability department. Somebody ought to be demoted.

Summary

Likes

  • Compact size

  • Battery option

  • Collins filters

  • Good audio

  • Lots of bands/modes

Dislikes

  • Too big for mobile

  • Not enough buttons

  • Not enough knobs

  • Too many menus

  • Mediocre RX performance

  • Limited battery life

  • Horrible display

  • No built-in TTL level converter


A jack of all trades, master of none radio. Probably most useful as a first response portable field radio. For other applications, look elsewhere.

Monday, November 19, 2007

Elecraft K2 Review

I recently completed my base Elecraft K2 amateur radio transceiver kit with the SSB adapter. The build took me about a year. Well actually it only took a couple of weeks of working on it a few hours a day, but then it sat at the 99% completed stage for about a year until last week when I finally wired up a microphone.

I've built a few kits before. Certainly never anything so complex. But I am pretty experienced with soldering and as an electronics technician, so I dove right into it.

There is an awful lot of soldering. If you are going to build this kit, do yourself a favor and invest in a good soldering station, like a Weller. The el-cheapo temperature controlled irons don't work worth a darn, I know from experience. A Panavise is a really good idea as well. The alligator clips on the helping-hands will chew up your PCBs.

Winding the toroids was fast and easy. I don't know what everybody is whining about. You must have awfully fat fingers if you can't thread a wire through a toroid.

Aligining the filters is tricky at best. This was probably my least favorite part of the build. I used a high-accuracy HF RF signal generator and a PC spectrum analyzer program to do it. You could ballpark it by ear but I wouldn't want to.

Overall, the build was complex and took a long time. But I made very few mistakes and they were easily corrected. It wasn't difficult, actually quite straight forward, but very time consuming.

I built this radio because of the receiver. Compare the specs. It's got one of the highest performance receivers on the market. My on air experience confirms that this receiver doesn't bat an eyelash at a band chock full of kilowatts. It's a big gun contest radio trapped in a pea-shooter's body. On air testing in the ARRL Sweepstakes confirms that this receiver works great. It's highly selective and doesn't de-sense in the presence of strong adjacent signals. Other than maybe the K3, it's probably the best contest and DX receiver on the market.

Not much needs to be said about the transmitter. It's 15W. You either like QRP or you don't. I don't. I'm going to build the KPA-100 hundred watt power amplifier ASAP. I do get good audio reports which IMO is all that really matters in a transmitter.

I've heard some complaints about fit and finish. I think it's up to par with most other rigs on the market. Maybe just a tad behind. The POTs are a little flimsy, I worry about their long term survival in a rough environment. But they're obviously user serviceable hi hi. The mechanical construction of the chassis is a bit different but seems rugged enough to me.

My only real mechanical complaint is the crazy way the finals are heat sinked, making removal and installation of that one panel a very fiddly operation with a lot of small parts to get lost. One of these days I'm going to glue all those parts together to minimize the chances of any one getting lost

As for usability it's great. It has pretty much all of the buttons and knobs I want right on the front. I very rarely have to delve into the menus. Compare this to my FT-897, I'm almost constantly scrolling through different button functions during normal ops.

My only usability complaint is the dedicated digital voice recorder buttons. I wish I could reassign them since I have no intention of installed the DVR module. If I want DVR I'll use my PC. Perhaps this could be fixed in firmware.

Missing features:
  • SWR metering in the base kit would be nice. It is provided with the KPA-100 module and also I assume in the ATU modules.
  • Mic gain. I know it's supposed to be automatic. I still like to adjust it myself. Maybe there is a way that I'm not aware of.
  • Remote front panel. I really miss this. As small as it is, mounting it in a modern vehicle is not trivial. None of the mobile rigs have receivers anywhere close to the K2.
  • VHF at a reasonable cost

Caveat emptor:
This radio is deceptively expensive. You should seriously consider your priorities and add up the total cost of the base rig plus all of the modules you intend to build before purchasing it including transverters. If all you care about is QRP CW on HF, then it's probably a great deal. Add SSB, it's still pretty reasonable. Add the 100W amp and the DSP and noise blanker and you're getting up to about $1300, which is still reasonable considering how awesome the receiver is. Yes you could almost buy an Icom 746Pro for that price, but no you would not be getting the same radio. The Icom is about bells and whistles. The K2 is about performance. It's like comparing a Ferrari to an Escalade. They both go fast but one has a lot more buttons and the other can drive circles around the first. Do you like making contacts, or do you like pushing buttons?

Do you want to work VHF? If so figure another $350 to $400 for an Elecraft transverter for each band you want to work. Plus $100 for the transverter interface board. Now the little bugger starts to get a heck of a lot more expensive than many other radios with similar features. It will probably perform better than just about any other radio on the market, but if you just want to get on VHF and aren't serious about winning the contests, maybe a K2 isn't the rig for you.

Summary:
The K2 is a premium product with premium receiver performance at a premium price that goes up quickly depending on what capabilities you want to add. The build process is long but rewarding. The result is a contest winning, DX working HF ham radio with one of the top receivers on the market and lots of great features packed into an efficiently compact unit that you can fix yourself.

Running QRP on a K2 in the ARRL Sweepstakes SSB

The ARRL Sweepstakes is one of the most popular contests in ham radio. I entered QRP this year so I could put my recently complete Elecraft K2 through the wringer. Well, the receiver works great! No matter how strong an adjacent station is I can still hear the weak ones next door. Excellent performance. I just need the auto-notch filter in the DSP module and I'll be set.

The transmitter is another story. 5W is a good way to get the snot beat out of you in this contest, especially considering the poor band conditions. When you are running 5W and everybody else is running 1500W and they are barely over the noise, you don't have much of a chance. And when I did manage to work people I got the impression they were annoyed that I was hurting their rate because I had to repeat so much info. And nobody seemed pleased to find out I was in SDG and not 1-land either. A real antenna would have made a big difference as well, a random wire on a fence isn't so hot. Oh well, maybe Santa will bring me a KPA-100. Or a K3 (drool). And as long as I'm making my xmas list I'd like a crank up tower with a 4 el steppir.

All that said I was actually surprised at how GOOD the bands were. From San Diego I heard openings to almost every part of the country, including VT, SFL, AK, PAC, BC, AB. I was really surprised to find 15M open Sunday afternoon, and to actually make a few QSOs on it with my
pea-shooter. I guess Tad Cook is right, the bands really are open more than we think!

The bottom line is that the K2 worked great in the contest, the receiver kicks butt. But life's too short for QRP, so I'm going to build the KPA-100 ASAP.

73 de n1ywb