PA1JIM

Blog mobile ready

PA1JIM — Thu, 24 Jun 2010 12:18:51 +0000

It bugged me for a while that my blog looked crap on my iPhone. Way too big, you always had to zoom in to be able to read the articles. “Had” because I found a simple solution. Running my blog on WordPress I’ve downloaded WordPress Mobile Pack and the mobile theme from Carrington Mobile 1.1 Theme from Crowd Favorite. And after 5 minutes my blog is mobile ready!

Kenwood SP-31 speaker

PA1JIM — Tue, 18 May 2010 12:30:40 +0000

Last piece of my Kenwood TS-850-line has arrived! The Kenwood SP-31 speaker. I already had the chance to play with one when the TS-870 for the club was temporarely in my shack. A beautiful speaker, not only to look at, but also the filters do a fantastic job. And most important: my TS-850-line is complete now! I’ve got the TS-850 transceiver, the PS-52 power supply, the SP-31 speaker and the MC-60 microphone!

I always wanted to build a piece of wooden furniture for this Kenwood line. Something that I could put on my desk so the gear is not placed directly on the desk but a little higher. Better view on the display, easier to operate and safer in case if anything wet (drinks) falls on the desk. It should be something fancy like mahogany or so. Nice shiny and chic! Mahogany is too expensive at this time, but I will make something more suitable.

Aligning a FT-817

PA1JIM — Tue, 04 May 2010 07:22:25 +0000

My precious FT-817 still is lying around in the shack unable to transmit. I’ve studied the service manual and did some measuring around in it. Regular readers of my blog know that a while back suddenly my Yaesu broke down due to shortage. It seems like a capacitor on the voltage input blew and took something with it. I let the input fix by a local service shop but that alone cost me already 75 euro’s. So now the Yaesu is able to receive again, but still no transmit.
My intention is to fix that myself. The local repairman told me it’s probably due to blown finals that the rig isn’t transmitting. That would make me a member of the “Blown Finals Club”. But I’m not quite convinced by his story. When only the finals are blown, you should get a very faint signal as output. But there is absolutely no signal at all. Not even when I take another receiver and poke around with that antenna in the transmit line of the Yeasu, no signal at all. So maybe the oscillator or driver stage must be (also) broken to get this behavior.

This would be my very first big repair job, there for I’m not in possession of various measuring equipment. The only measuring device I have is a multimeter. That won’t bring me very far in this case. Fred, PA3YH has a Multimeter which can measure HF-signals. A RF-millivolt meter, such as referenced to in the service manual. But it has a maximum reading frequency of 100 KHz. The RF-millivolt meter reads like 2,6 volts AC on the output of the oscillator (the service manual says it should be 66mV). But the output signal from the oscillator has a frequency of 65.875 MHz. So it’s logical the meter is not reading the correct voltage.
Okay, so I don’t know if the output of oscillator is correct, but I DO know that the oscillator has output! So I guess now I should look to the first driver stage.
But I think I’ll look for someone with a good scope first. It’s easier to check all the checkpoints in the service manual and also check if they have the correct value.
If anyone has good tips on how to find the problem, let me know!

Unidentified Signals

PA1JIM — Sun, 02 May 2010 11:05:27 +0000

When I was tuning around at the band the other day, I mistakenly went out of band and ran into a pretty strong signal. A weird signal. When I spin around some more I’ve noticed this signal repeats itself all over HF. First I thought its something in the neighborhood but when I asked Fred, PA3YH and Anne, PB1A to listen for the signal, they confirmed it.

I’ve made a list of all the HF frequencies were I hear this signal. Does anyone know where this signal is coming from and what it is? Are there more HAM’s who hear this?
Listen to the mp3 here: Unidentified signal JO22NF
The list of frequencies is over here: Frequencies Unidentified Signal

bhi NES10-2MKII

PA1JIM — Sat, 01 May 2010 10:03:01 +0000

A while ago I’ve bought a DSP-speaker from bhi, the NES10-2MKII. The results with this speaker are unbelievable. The background noise is totally pushed away and you’ll be able to hear signals that are normally buried in noise. So the DSP-algorithm is very good. However…… I’m not satisfied with the LF-amplifier in the speaker itself. It hums and makes noises when it has no input. When you crank up the volume too high the speaker starts making distorted sounds. First I thought it was the speaker itself, but when I put the thing inline between my rig and the Kenwood SP-23 speaker the distorted sound appears from the Kenwood speaker. Really unsatisfying when you take in consideration that the DSP-unit itself is doing a great job.

I would really like to add the ‘bhi-experience’ to my TS-850 and TS-450. But I prefer a way without the crappy LF-amplifier from the NES10. I’ve a external speaker for as well the TS-850 as the TS-450. So it would be an option to put something in there. But I don’t want to drill extra holes in those speakers. It would also be an option to put a DSP-unit in the transceiver itself. I read from the bhi-site they have an unit for building in transceiver too: the NEDSP1061-KBD. Although tis unit is mainly made for adding to a Yaesu FT-817 or a Kenwood TS-50, it is possible to build it in other transceivers according to this manual to build it in a TS-440.

Now would it be possible to also build the NEDSP1061-KBD into a TS-850 and TS450? Does it have the same performance as the NES10-speaker as regards to the DSP-functionality and I’m I rid of the bad LF-amplifier behavior this way?

Just some questions and it would be great if someone have already experience with the NEDSP1061-KBD. Let me know!

Neighborhood noise

PA1JIM — Fri, 30 Apr 2010 07:59:48 +0000

The other day when I was testing my brand new Cobwebb antenna I noticed something weird. I worked a few stations (EA7IQQ, RV3DMX and RV9LM) and I was pretty happy with the results so far. So I went on the roof to do some finishing touch on the Cobwebb. A little tape here and there to make it a little more waterproof.
When I came back down and listen again, the noise level increased from S1-2 to S8-9! At first I was thinking: maybe the band just closed when I was on the roof. Still it’s a weird thing for the noise level to come up.

But then again I remembered changing something else: I rotate the Cobwebb to be able to reach the elements. So it was in a different position now. Not that that should matter, the Cobwebb is multi directional. Time for a new experiment: the XYL behind the s-meter and me on the roof turning the Cobwebb around. Results? When I turned the front side of the Cobwebb (where the element ends are bound together) to the east, noise level drops to S1-2. When I turned the front in any other direction, noise level increases from S5 till S9! If you take a look at the construction of the Cobwebb, you notice there is less length of element in the front side. Maybe the Cobwebb is multidirectional from a bigger distance, but maybe when a signal (interference) is nearby, the Cobwebb behaves a little directional. It seams like there is a big interference east from my house. When I look at the other side of the street, there is a big old peoples home there. Maybe the source of interference is located there. Time to find out more about this. Although not sure how to begin… Any tips?

First impression Cobwebb 0.2

PA1JIM — Thu, 29 Apr 2010 07:35:39 +0000

A while ago I did a first try to build a Cobwebb antenna. I noticed that even on a very low operating height (about 2 meters above the ground) the Cobwebb received very well. Last weekend I did my second attempt to build a Cobwebb antenna for 10, 12, 15, 17 and 20 meter. Gave the construction a little more thought and this time I tuned the wires individually before putting the Cobwebb on the roof. I’ve made sure every element was resonant within the amateur band. No problems. When I put the Cobwebb on my dormer, this thing works like a charm!

On the receiving part I notice very strong signals. The signal strength seems the same as on the 3 elements beam over at the club. Weird thing though is sometimes at 20m suddenly there is an enormous noise level. Up to S8! But a little later the noise level drops to S1 or 2 and I hear a great deal of signals from all over the world. Can it be the opening and closing of the band?

Genesis G3020 SDR

PA1JIM — Mon, 26 Apr 2010 13:27:19 +0000

Reminder to self: is this interesting to build?

BPSK31 first contacts

PA1JIM — Fri, 23 Apr 2010 14:33:23 +0000

Lately I’m not doing well on the antenna area. I did pull down the multiband dipole because it was really a horrible sight from the back garden. Then I put down the Antron 99A because it wasn’t giving the performance I hoped for (I couldn’t use it for 20m anyway). And the Cobwebb is still under construction which give a little delay because of the DYI-stuff I have to do around the house at the moment. So the only antenna I now use is a single wire which I draped over the roof. More of less in a square, 20 meters long.
I’ve noticed a pretty nice receiving signal in SSB but (of course) transmitting is awful. Not been able to make a single contact in SSB.
But the other day I got an idea: why not trying BPSK31?! So when I fired up the Signalink USB I started making QSO’s! A lot of European Russia (UA3PI, UA3GX, RA3FO, RN3DY, RX3DD, RU3EJ) but after trying a little harder I also contacted Croatia (9A6DJM), Ukraine (UX1MW, UX1LN) and Romania (YO3JX). This turns out to be fun! Fine tuning my macro’s a little here and there.
Seems that my wire on the roof has a liking for the east, don’t know why since it lays out in a square. But hey, it’s nice working till I’ve get my Cobwebb up and running!

Could D-Star destroy ham radio?

PA1JIM — Tue, 20 Apr 2010 15:12:33 +0000

One of my favorite hamblogs must be the one from Julian, G4ILO. Julian always writes very sharp and critical posts, fun to read! I’m so happy he now implemented RSS to his blog so I can keep track.

This afternoon I was reading his piece about D-star. I’m not very familiar with D-star. Read a little about it, seen someone at the club with a portable transceiver making QSO’s with an American Ham. Didn’t like the digital sqeeks and blibs. D-star equipment also seems to be too expensive for me. But when I read this article from Julian (supposing he did his research), I don’t think I mis out on anything…