There are pretty standard balun kits that go from 2 to 30 Mhz. They are very low loss and generally less than $20. Google "balun kit".

Yes, you can buy SWR meters that work on HF and lower. Check out MFJ. They are also easy to build.

Mark

 

There are pretty standard balun kits that go from 2 to 30 Mhz. They are very low loss and generally less than $20. Google "balun kit".

Yes, you can buy SWR meters that work on HF and lower. Check out MFJ. They are also easy to build.

Mark

Thanks. I checked out MFJ and discovered a cost of about 150 dollars for one that worked with HF. That means it's going to have to wait until I want one bad enough.

 

Also check the "pretty easy to build part"
Not much more than a tapped coil and two tuning gangs (or just one for rx only).

Thanks. I checked out MFJ and discovered a cost of about 150 dollars for one that worked with HF. That means it's going to have to wait until I want one bad enough.

 

Also check the "pretty easy to build part"
Not much more than a tapped coil and two tuning gangs (or just one for rx only).

Thanks, Art. I have looked into that easy to build thing and I have seen that it's iffy. I am batting about 200 (that's baseball for about 20 percent) when it comes to success with circuits I really don't understand.

I'm kind of reluctant to try my luck. All work and little success makes Paul a very dull boy.

 

You can hardly go wrong, for receive only you don't even need a box for it.
This one is for listening only:
http://www.hard-core-dx.com/nordicdx/antenna/lab/tuner.html
The stuff you've already done is way ahead of an antenna tuner.
An antenna tuner is everyone's first project for their beginner radio license.
So much so, it's so easy some clubs have banned it as your first project.

Thanks, Art. I have looked into that easy to build thing and I have seen that it's iffy. I am batting about 200 (that's baseball for about 20 percent) when it comes to success with circuits I really don't understand.

I'm kind of reluctant to try my luck. All work and little success makes Paul a very dull boy.

 

Interesting article, but I'm familiar with inductors in parallel with a tuning capacitor as used in most commercial radios. Lestraveled was talking about a meter that is capable of determining the Standing Wave Ratio between the transmitter and the antenna. A low ratio (I've read 1:1 or even 1.5:1) means a good match.

 

Not a whole lot more difficult to make, just difficult to calibrate without an existing unit.

EDIT,,,
You would have fun at a hamfest whether you're licensed or not.
You can just buy some old junk for small money and break it.
They have CB stuff as well, just as relevant, but the old 27MHz gear is cheap as dirt now unless it's some classic gear.

I got a SWR/PWR meter for 27MHz CB at my last one for $10 just to break it.

Then when you get into ham radio you know you're getting ripped off paying $200 for a meter movement,
some resistors and a diode.

 

There are several things that I think PRS should consider. First the low power rating he is using right now will not even give an indication on a SWR meter.
Second a SWR or 1.5 to one is not worth worrying about as the reflective power is only .5%

 

Not a whole lot more difficult to make, just difficult to calibrate without an existing unit.

EDIT,,,
You would have fun at a hamfest whether you're licensed or not.
You can just buy some old junk for small money and break it.
They have CB stuff as well, just as relevant, but the old 27MHz gear is cheap as dirt now unless it's some classic gear.

I got a SWR/PWR meter for 27MHz CB at my last one for $10 just to break it.

Then when you get into ham radio you know you're getting ripped off paying $200 for a meter movement,
some resistors and a diode.

Buying stuff just to break it and see how it works makes sense to me but only when I'm working. I gave up my job a couple years ago and money is hard to come by now. But I have a whole bunch of stuff on hand that I bought when I did have money. And, as you pointed out elsewhere, it could be expensive if I get caught broadcasting rf without a license to do so. Therefore I'm scaling down my ambitions for now and I'm going to confine myself to the house as far as power goes and make sure I don't interfere with public broadcasting in any of its forms. I am an experimenter and that is all. The technology intrigues me. I'm not really building a radio, just exploring its elements, so to speak.

I have come to the point where I can modulate and demodulate AM, and I can demodulate FM, but modulating FM is a current problem and I will soon address SSB. I can at this moment produce a DSB signal (without the carrier) and I suspect a Collins Mechanical Filter will create the SSB.

But for all of that, I am currently able to modulate and demodulate AM and this leads to the actual communication I'm interested in. I played with PIC microprocessors last year and I'm considering using them as serial communication devices. It seems to me it wouldn't be hard to have them talk to one another via radio using their serial ports and modulating their outputs onto a carrier. It seems to me it doesn't matter whether their digital output be modulated/demodulated using AM or FM or whatever; it's all just a matter of modulation and demodulation whatever it be.

 

There are several things that I think PRS should consider. First the low power rating he is using right now will not even give an indication on a SWR meter.
Second a SWR or 1.5 to one is not worth worrying about as the reflective power is only .5%

Thanks, k7, I'm in the learning mode. Some day, if the Lord be willing, I will be savvy about antennas and SWR meters.

 

It seems to me it doesn't matter whether their digital output be modulated/demodulated using AM or FM or whatever; it's all just a matter of modulation and demodulation whatever it be.

That's pretty much the bottom line as long as you have no restraints on bandwidth or noise levels but as soon as you enter the 'real world' of RF communications things like the manner of modulation start to matter if you need error detection and correction while getting the best end-to-end error free signal speed from a channel.

A simple ASK system might be a place to start.

 

That's pretty much the bottom line as long as you have no restraints on bandwidth or noise levels but as soon as you enter the 'real world' of RF communications things like the manner of modulation start to matter if you need error detection and correction while getting the best end-to-end error free signal speed from a channel.

A simple ASK system might be a place to start.

Thanks nsaspook, I followed your link about ASK and not I'm a little confused. Is ASK conducive to Morse Code type of radio? What distinguishes it from simple on/off transmission? As I see it on/off is binary and readily adaptable to serial RS232 communication. Morse code is not in that it relies on the duration of an on state. A dot is short, a dash is long, thus time duration is introduced into the transmitter's or receiver's ability to distinguish information.

 

Hello PRS, Your in luck good buddy. For many, many years now, the FCC has allowed low power, unlicensed transmission on certain segments of almost all frequency bands. It's being used all over the country for industrial control mostly. But it has become a big hobby item now. It started out with the VLF crowd trying to pick up submarine transmissions. Now there are beacons at all kinds of frequencies, broadcasting email addresses so people can contact beacon to report time, location and signal strength. There are groups and clubs all over. I used hundreds of these low power units for rs-232 data transmission in the late 90's. Now they come with usb! Just search google for low power transmission or radio. Until then, keep the shiny side up and the greasy side down, good buddy.....rodger and out.

 

That's interesting. But I'll still keep my experimental stuff in the house just out of courtesy. Who knows where any harmonics might be going? By the way, what form of frequency modulation did you use for rs-232? I'm about to do the same thing and I'm thinking I like FM because of the low noise figure.

 

Thanks nsaspook, I followed your link about ASK and not I'm a little confused. Is ASK conducive to Morse Code type of radio? What distinguishes it from simple on/off transmission? As I see it on/off is binary and readily adaptable to serial RS232 communication. Morse code is not in that it relies on the duration of an on state. A dot is short, a dash is long, thus time duration is introduced into the transmitter's or receiver's ability to distinguish information.

I don't want to start another is Morse binary thread but yes ASK can be simple off/off to encode Morse (a protocol not a modulation) or 1 bit binary per symbol or multi-level where a four modulation level ASK system could encode 2 bits of information per symbol.