September 2010

Thu Sep 02 07:31:48 PDT 2010

What is it About Insurance Companies?

Since I updated my résumé on CareerBuilder, I have been averaging about one spam message a day from insurance companies asking me to consider becoming a commission-based agent for them. I will point out that my résumé makes no mention whatsoever of either sales or the insurance industry, and that no other industry has spammed me once about sales positions.

Then again, I think it’s obvious. We’re talking about the industry that first fought, then corrupted beyond belief any concept of universal health care in this country, despite the ample evidence showing how lack of same hurts and kills people. What’s a little spam to those who consider killing in the name of profit worthwhile?

Thu Sep 02 19:49:40 PDT 2010

Was He? I Believe He Was.

Was Banksy in Portland? that is. Part of it is that I simply want to believe he was, since I did notice the umbrella girl recently. And part of it is that if it wasn’t him, the pieces are very good imitations.

I just don’t think someone else would try that hard; it’s not like there’s any money of fame in it. Nobody knows exactly who Banksy is, and he doesn’t make any money by secretively painting walls. If someone else wants to do street art, why would they want to be mistaken for another, more famous artist? Far better to just adopt one’s own style and do that.

Moreover, Banksy is known to be in the USA this summer.

Sat Sep 04 14:19:45 PDT 2010

Fixing the Lowe HF-150 BFO

(This is going to be a very geeky post. If you’re not into electronics, you should probably just skip it.)

My Lowe HF-150 shortwave receiver has been plagued by a problem with its BFO for a number of years now. Particularly at warmer temperatures, it suffered from frequency instability. This ended up making the synchronous detector (one of the strong points of this model of receiver) all but useless. Recently, it’s been bad enough to make it impossible to listen to SSB signals as well, so clearly action was required.

Last month, I did some searching on Google and found an article which described the problem I had been plagued with fairly closely. I just finished replacing Q4, the troublesome type MC14569 IC, which lies just under the front frequency-display readout (which thankfully is socketed for easy removal). It’s a little early to definitively announce success, but the BFO seems to work better than it has in many years. The synchronous detector actually works well now.

If you’re taking apart an HF-150, there are a few tricks to it. In only rough order of importance, here they are from memory:

  1. Removing the on/off/volume knob (which you need to do in order to remove the front panel) is probably the trickiest thing of all. It doesn’t have any visible holes for a set-screw to be loosened, making it look like it’s held in place by a friction mechanism. I ruined the volume control on my HF-150 under that assumption (I have a bad sense of when to force things and when to be reluctant to do that, particularly on anything newer than the vacuum-tube era). There is a set screw to loosen, but it’s very well hidden. The knob has a front cap that pops off, and the screw is underneath that.
  2. The tuning knob is held in place by a 2.0mm hex nut and is straightforward to remove. Once you have removed both knobs, remove the four 2.5mm hex screws at the corners of the front panel, the Phillips screw hidden behind the tuning knob, and the Phillips screw at the upper-right corner of the display window, and the front panel will come right off.
  3. Next, remove the four metric hex screws and one Phillips screw that hold the back panel to the case. Now you have to remove bottom panel (very straightforward; just remove the four small black Phillips screws). Once you do that, you can remove four more Phillips screws holding the main circuit board to the case.
  4. At this point, it is possible to remove the innards of the set from the case. The trick is to slide the board sideways, and you’ll be able to free it from the case. You have to be a little careful because of the cable connecting the speaker to the circuit board. Note that the back panel is still attached to the board at this point; it does not need to be removed in order to perform this repair.
  5. The electronics is mounted on two circuit boards that are soldered together at right-angles. Q4 is located on the front panel, at the left edge of the frequency display and partially beneath it.
  6. Use a marker to make a witness mark on the upper-left pin of the frequency display before you remove it. (Maybe there is one already there, but I didn’t notice any, and you’ll destroy this irreplaceable part if you plug it back in the wrong way.) As mentioned, the display is socketed for easy removal, but it is a delicate, mostly-glass part, so be very careful removing it.

Everything else is just the garden-variety tedium of desoldering, removing, and replacing an electronic component, followed by reversing the steps you took in taking the set apart.

One final thing: The chances of being able to find a given IC at a local retail electronics store are essentially zero. If you’re like me and seldom buy such things, the minimum orders that mail-order parts houses impose end up being pretty onerous. What I did is ask one my more electronically-inclined friends if I could piggyback onto his next order for parts.

Thu Sep 09 07:41:17 PDT 2010

Suggestion to the Media: Ignore Right-Wing Idiots

Really, now, if some right-wing idiot of a pastor wants to burn some books, the only real issues are whether or not the books are legally his to burn, and if the fire is personally endangering others or their property.

Both are matters for the local municipality and the local press. There is no need to give the guy national (or, worse, international) news coverage. Doing so is playing straight into his hand; witness the adage "There is no such thing as bad publicity."

Right-wing idiots will do stupid things. It’s what makes them right-wing idiots. Stupidity is, alas, a very common thing and thus is rarely newsworthy.

Thu Sep 09 18:31:05 PDT 2010

Lowe HF-150 vs Palstar R30A

After playing with my new toy for a day, here’s my first impressions, particularly in comparison to my Lowe HF-150 But first, some disclaimers:

Now, on to the comparison:

All in all, no big surprises. The Palstar has the features for which I purchased it; I am eager to get away from the big city and put it to the test.

Tue Sep 21 18:35:37 PDT 2010

Palstar R30A Redux

Executive summary: the thing has problems with birdies, particularly related to the display driver.

The gory details: All went fine on my first backwoods listening session, until I chanced to listen to Radio Australia late in the night on the 22m band. “That’s odd,” I thought to myself. “It sounds like I’m picking up my roommate’s computer, yet I’m at least twenty miles from the nearest PC.”

Very odd indeed. Sure, it’s not precisely a strong signal, but there should be absolutely no interference at this location! I tune around the 22m band and find computer-like noise at various spots. It’s never very strong, but it’s there. And when it interferes with a weak signal, it makes for a most annoying high-pitched warbling noise in the background.

“Could it be that my R30A is full of birdies?” I wondered. Unfortunately, I had no way to know for sure, having not brought along any other receivers to compare with.

When I get home, I try an experiment. I turn on the R30A with nothing connected to the antenna; the odd computer-like noise is still in the same places. Even more damning, I connect a piece of wire to my Lowe HF-150’s antenna input and run it in front of the R30A’s display. I can now hear the R30A’s birdies on the HF-150!

On my next listening foray, I take both the R30A and the HF-150 along. The unpleasant truth soon becomes apparent as I listen to the Voice of Russia on 13775 kHz, which happens to be one of the places where the R30A has a weak but definite birdie. At first, it’s a strong signal and perfectly listenable, but it starts fading out. At that point, a most annoying high-pitched warble starts becoming all-too-apparent.

I switch to the HF-150 and tune to the same frequency. A weak signal with some static hiss in the background, but it’s completely listenable now that the annoying warble is gone.

I will say that the Palstar does appear to be a very sensitive and quiet receiver… when its birdies aren’t getting in the way. There’s no birdies at 5505 kHz and Shannon VOLMET was clearly readable despite the signal usually not being strong enough to even deflect the S-meter. (I’m on the USA West Coast and was using only about 20 feet or so of random wire tossed into the trees… pretty impressive to pull in a station from half the world away that I believe uses all of 1kW into a non-gain antenna!)

Of course the rub being, the HF-150 is quiet and sensitive everywhere. Shannon VOLMET was every bit as listenable on the HF-150 as it was on the R30A (pity the HF-150 is so awkward to use in USB mode, thanks to its painfully slow tuning rate).

Anyhow, at this point I’m reasonably sure I have a factory defect; the R30A is highly-rated, and some of its raters mention the lack of birdies as the reason for their ratings. I call up Palstar and talk to their engineer. The conversation starts out roughly on the following lines:

Me: I think my R30A is defective. I’ve noticed quite a lot of birdies on it.

Paul: Did you try using the radio without an antenna connected?

Me: Of course. [Comment: Really, now; it’s only logical to do that; one must rule out noise coming in from outside the set.]

Paul: Why are you listening to the radio without an antenna? That makes no sense.

Me: [Taken aback that an electronics engineer would ask such a question in this context.] Well, I wanted to be sure that those noises I heard were actually birdies and not something off the air.

Paul: All receivers have birdies. You have to tolerate them. What kind of antenna and ground were you using?

Me: [Makes the mistake of telling him, instead of saying that the question is irrelevant because my HF-150 works fine with the precise same setup.]

Paul: [Starts talking about antennas and counterpoises.]

Me: I realize that my setup is suboptimal. Yet it works just fine with my Lowe HF-150. I have no problem with birdies on it when I’ve done a side-by-side comparison. Signals that have an annoying high-pitched warble on the Palstar are perfectly clean on the Lowe. I have a hard time believing this is the fault of my antenna setup.

At this point, he does start offering to let me return the receiver, not because there’s anything wrong with it, mind you, but because I’m so unreasonably hard to please.

All in all, a most disappointing outcome. And the Palstar came very highly-rated. Why? I have several theories:

  1. The growing RF jungle. I’m not alone in living in an environment that makes shortwave reception difficult. These days, most people do. If you’re in a high-noise environment (or even a moderate-noise one), you’ll never come close to hearing the Palstar R30A’s birdies.
  2. Declining standards. Modern radio receivers have computers inside them. Computers make RF noise. The two do not get along well together. Most people have stopped remembering what things were like before computers got into the picture and compromised receiver noise floors. They have forgotten that things were once better.
  3. Poor quality control. My set is a lemon. Others have received plums. If I had received a plum, I wouldn’t be typing this; I'd be raving about how quiet the set is.

The first and the third are plausible explanations. I have a difficult time believing the second. Computers doubtless complicate design issues, but I doubt they doom receivers to being full of more birds than an aviary. My Lowe HF-150 has a computer inside it, and Lowe managed to figure out how to keep it from making bleeps and burbles all over the HF spectrum.

Anyhow, unless I come across some unexpected bit of information that makes me change my mind, it’s going back for a refund because this customer is not satisfied.

I certainly don’t think I’m being unfair. I’m being tough (for a variety of reasons, my backwoods listening setup is something of an acid test for internal receiver noise), but not unfair. If I were comparing a military-grade receiver with a five-figure price tag to the Palstar, I would be being unfair. Yet the Lowe HF-150 is (or, rather, was) in about the same price class as the Palstar, and it works just fine in the same situations.

Pity it’s so awkward to tune in SSB mode and has no dial light or S-meter, but if those are the quirks I must put up with to have a reasonably quiet receiver that works in the backwoods, I’ll cope with them. Makes me all the more pleased I invested time in fixing the BFO on it recently and restoring it to full health.

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