Put the rig in a box together with an ozone generator.

Tanakasan

Two observations:

1) I was brought up never to discuss sex, religion or politics in polite company. Talking about sex over the air will probably get you into trouble real quick and the other two subjects tend to get folk's gander up in a heartbeat.

2) Most people on this site are free to discuss political issues over the air but some are not. Not all IARU countries are politically free.

Tanakasan

Put up a sign on the gate saying DOBERMAN PUPS FOR SALE 

Tanakasan

Hi Rose

Congratulations on passing the Extra exam. If you want a little inspiration to go further then have a word with either Tisha, AA4HA or Allison, KB1GMX, both of whom contribute on a regular basis to Eham and various Yahoo boards. I don't know much about Tisha but Allison has done some mighty fine engineering work over the years and her knowledge has, in my case, proved invaluable.

I look forward to reading your article in QST.

Tanakasan

P.S. Extra women? No thank you as I'm quite happy with just the one (and typing this with the XYL looking over my shoulder   )

Hi Julia

If you have the radio working on Medium Wave and you managed to receive some of the WWV time signals then it's a start. The reason for my post is a quick explanation of the weird noises and the chipmunks when you pressed the SSB button.

When you tune in a broadcast station on Medium Wave you are trying to receive a station that is transmitting AM or Amplitude Modulation. As you tune across the transmission you will find that clearest reception is in the middle of the signal and it gets weaker either side.

The ham radio broadcasts are different because we use either CW (Morse) or SSB (Single SideBand). When you press the SSB button you're turning on an extra section in the receiver called a BFO or Beat Frequency Oscillator and this is essential for receiving CW and SSB signals. A picture of your receiver shows three knobs on the side, Tuning, Volume and SSB BFO and all three knobs need to be adjusted for clear reception. A rough guide to tuning in is as follows:

1) Tune across a short wave band until you hear the high pitched voices

2) Alter the BFO knob until the pitch changes and voices get clearer

3) If no position of the BFO knob works then move the tuning control a little bit and go back to step (2).

One other thing that may help is a better antenna. Thirty feet of wire thrown out of a window or across the nearest tree will probably bring in a lot more stations.

Hope this helps!

Tanakasan

Bill Kelsey, the Owner of Kanga US had a stroke on March 8th. Right now the impact has been weakness in
his right arm and leg and difficulty with speech and swallowing. His memory has not been impacted. He was air lifted from Findlay to Ohio State Medical Center in Columbus and is being treated there. Currently they are expecting time and treatment will yield a full recovery.

His wife  has asked that people not email or telephone them until further notice. Kanga US will obviously be out of action for an undetermined amount of time.



Tanakasan

The contacts on a lighter plug are not very good, the fuse may be rated at 10A but I doubt that you could pull more than 2A or 3A from one without it getting hot.

A 400W amplifier (assuming 50% efficiency) will draw 800W @ 13.8V. This is a 58A load and a fire waiting to happen unless you do it right. Head for Alan's site and do the job properly.

http://www.k0bg.com/wiring.html

Tanakasan

Thanks for the links although this is now a very old topic. Most of the links point towards 455 KHz or 10.7 MHz transformers but three of the Mouser devices MIGHT work as they come without capacitors. What I ended up doing was using some Minicircuits transformers and instead of having a variable inductance and fixed capacitor I used a fixed inductance and a 20pF trimmer.

Tanakasan

OK, found it, Ham Radio Magazine October 1975 pages 26 to 30.

Dr. Rohde uses a grounded gate FET amplifier where as modern techniques favor the use of a diplexer, either way you need to make sure that the mixer sees 50 +/- j0 on all three ports. The screening in the schematic shows that all three ports are isolated plus there's another screen between the source and drain on the FET. There's even a novel screening arrangement between the input and output pins on the first IF filter.

If you post an email address I'll send you a PDF copy of the article.

Tanakasan.

"It takes a lot to run the worlds most effective pyramid selling scheme"

Amen to that, although as a member of the Red Sea Pedestrians Club I should point out that we got there first. 

Tanakasan

Years ago in Ham Radio magazine there was an article on high performance front ends by Ulrich Rhode. If you can find a copy (I'm still looking for you) then read through that because it gives you all sorts of layout tips. One thing I do remember is the amount of shielding he used including shields between the pins of the mixer.

If I find the article over the weekend I'll tell you which edition it's in.

Tanakasan

"Sometimes, when doing r&d for your own use it can be fun (and educational) to see just how far you can push an idea."

Oh yeah! Now why can't the majority of the amateur population think like that? As soon as I read that comment I was reminded of the 'Huff and Puff' oscillator stabilization system which started off as quite a complex piece of electronics and ended up as two or three chips.

“Everything should be made as simple as possible, but no simpler.”

Albert Einstein



Tanakasan

If you find one let me know. In thirty years of ham radio I've never found a rig with an effective noise blanker and when it came to designing my own rig I left it out without a second thought. What I HAVE found to be effective are the external boxes which use a separate noise antenna and then phase inversion to cancel out the interference. The Timewave ANC-4 is a good example of this: http://www.eham.net/reviews/detail/1138

Tanakasan

An interesting post. A long list of specifications only matters if the people reading the article can understand their meaning, and that ability is starting to wane. The latest 'product reviews' in QST seem to concentrate more on useability than anything else and they have even stopped showing pictures inside a rig so that we can get some idea of the construction quality.

I think the biggest problem is that we have reached a technological plateau and the manufacturers are either unwilling or unable to push the envelope. The same thing can be seen in the computer industry, I'm typing this on a six year old laptop that doesn't need to be replaced because it does what I want and if I should purchase a new machine it will only provide a minor increase in performance. To sell rigs (and computers, and flat screen TVs) the manufacturers therefore resort to adding bells and whistles through software in an effort to add perceived value.

So, what is the present state of affairs?

1) Receivers are about as good as they can be, although transmitters could be improved. The last truly revolutionary antenna idea was probably the StepIR.

2) Progress in technology seems to have slowed.

3) The people using these devices (computers or ham radio rigs) are being reduced to appliance operators because of the technical complexity coupled with software walled gardens.

4) The standard of technical education is falling with some purchasers of equipment unable to understand or appreciate the nature of their purchase. Specifications are ignored and new features are left switched off due to an inability to read and understand the manual.

Two weeks ago I had to explain to a licenced amateur  the difference between the emitter, collector and base connections on a transistor. This is a young man who owns a top of the line HF rig which he purchased the day after passing his exam. Something tells me he never read the specifications before purchase.

Tanakasan

I would love to find a way to add CAT control to my homebrew gear. The three DDS chips in the rig are already under microprocessor control but I have no idea where to start.

Having said that.............

It would be nice if CAT could be dragged kicking and screaming into the 21st Century with control over USB rather than an RS-232 cable. The only people I know who have come close to this are Icom with the IC-7600 but I'm willing to be proved wrong.

Tanakasan