Amateur radio - maintaining the technical standards

In the groups.io group, rsgb-workshop, those who might be considered to be the bell-wethers of amateur radio are bemoaning the decline in technical standards, especially among USA Extra class licensees who know not where to connect their SWR bridges :-(

Reply to
Gareth Evans
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Well one would hope at the aerial, but there are some clever devices around now called antenna analysers that you can place at the aerial feed point and also on the end of the feeder. Even I know that if you are using a doublet with a balanced feed back to the transmitter you tune the whole thing, but if its coax fed or has a balun at the aerial its really best to check the match there at all frequencies needed. If I were going to transmit, I 'd go the doublet way rather than the dipole fed by coax as the tuner can then be in the house and you stand a better chance of not having everything acting as an aerial in the house in my view. Really you don't need complex theory as long as you can work out the frequency to wavelength correctly and get as near as you can to 1 quarter wave at the frequency either side of the coax o an unbalanced system it kind of works,

Mind you good earth mats are very handy things for both receive and transmit.

I do hope more people would take an interest in direct point to point comms. Its probably the only way that will work if our modern world suffers an issue taking down the digital stuff. Brian

Reply to
Brian Gaff (Sofa 2)

We need to stress the difference between radio amateurs, those of a technical bent, and CBers-masquerading-as-radio-amateurs, those who only operate ready-made shop-bought equipment. I wonder if Harry Bloomfield M1BYT places himself in the latter category going by his rather silly and infantile approach to debate in an international forum?

Reply to
Gareth Evans

I reckon that the vast majority of them would happily tell YOU where to place an SWR bridge, Gareth.

Reply to
Bernie

High hole, high hole, it's off to twerk I go.

Reply to
Bernie

People who think there is a simple answer to that question probably don't really understand what they are doing.

Reply to
Roger Hayter

Test for you then ... I'd like to build a simple FM broadcast receiver that I can tune (and lock) to R4 for our daughter to listen to when she's out walking the dog.

A kit would be nice but I don't want anything that scans, unless it can be locked on a single freq (93.2 MHz?) at startup?

I think it would only need to drive a small speaker or single headphone.

Cheers, T i m

Reply to
T i m

There is also the elitist aspect to be considered.

Reply to
John

SiLabs make some very nice single-chip FM radio receivers. You can control the tuning over i2c. Some versions have support for actively tuning a loop antenna. All you need is one of those and a small microcontroller to preset the tuning.

John

Reply to
jrwalliker

I built something along these lines years ago. It was downconverted to

100Khz IF or so and then pulse counted to demodulate..

It's very possible to do this these days with all sorts of circuits being available.

Reply to
The Natural Philosopher

Anyone who has passed the RAE, perhaps you, is well qualified to pursue such a project, and taken with the self-training concomitant with the interest and the licence that you have held for a number of years, you should have no difficulty in either completing such a project off-the-cuff or with a little researching, completing it then.

Good luck with the project! (You are an example to the candidature of the exams today)

Reply to
Gareth Evans

Would that be this sort of thing John?

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Ok.

I'm not sure what that means and how it would apply it's use when dog-walking. ;-)

So would require something like an Arduino Nano / ESP32 along with the radio module *just* to do that (lock it to R4)? No way of mapping it using jumpers etc?

I think I was thinking of something much simpler, possibly with just a preset tuning cap, rather than anything digital that's probably going to consume more power for no real advantage in this role?

I'm not ruling out the idea of a digitally controlled FM module, especially if it might out-perform a more basic solution (stability AFC/ AGC etc).

Part of the point was for me to give her something simple that just did R4 with a volume control, and ideally at a budget price. I fear once we start down the road of something 'nice', all be it locked onto

93.2 MHz, I might as well by a manually tuned small commercial 'transistor radio' and glue the tuning knob on R4. ;-)

Cheers, T i m

p.s. I have previously been given (as a promo) micro radios with no display and a simple search button and volume control but they didn't typically retain the last used frequency and would also 'search' on their own if the signal dropped out for a second. ;-(

Reply to
T i m

No actual help on that then, you know, in the true spirit of RA (or just some elitist posturing and hot air)?

It will need more than luck to have it locked on 93.2 MHz.

Exactly. You seem very confused re what 'most people' are willing to input into 'a hobby' these days.

As I said, I didn't take my RAE to start running long wires down my garden, talking to people using a series of beeps or talking to anyone for that matter, it was *purely* to be able to hook my PC up to a digital network and move data / Emails.

The 2 FT23R's we have were to be used as walkie talkies, not to advance the concept of amateur radio.

I attended the RA course at a local college and as a surprise, so did my (pregnant at the time) Wife. She had to study hard (and we helping her) whilst I had covered most of it previously so didn't really need to learn much to get a pass (that was all I cared about). I think she passed and I got a credit (or credits?).

She has only ever used hers to be able to transmit with the handy and mine running the Packet station.

I did assemble a couple of BSX2 TNC's [1] but that was more in line with my job at the time as a Data Communications support / service Tech, a massive leap from that to *designing* RF stuff.

So, it is likely the case that *your* interpretation of the needs and desires of anyone looking to get into RA today (who is under 40) is more likely to look at it from an off-the-shelf, buy it and run it POV, rather than someone winding coils round pencils or *designing* anything.

Look at the market for kitcars, self assembly RC models or the demise of electronics / components shops / or general hardware suppliers to see that.

Even though I'm old, 'into electronics' and know a lot of technical / PC type people, the only other RA I know in person is Brian. ;-(

I did attend a local radio group natter night but felt just as uncomfortable as I did when I went to a Linux group one.

All weirdo's. ;-) Cheers, T i m

Reply to
T i m

Yes. Those ones allow you to use the headphone leads as an antenna. There are some others that support a small loop antenna. Such loops are narrowband, so the radio can autotune the loop for the frequency currently being used. This gives much better performance than a fixed tuned loop and compensates for varying proximity to other objects such as the person wearing it when dog walking.

See above

These ones do need a microcontroller, but an ATtiny or similar minimal processor should be enough. You would need good soldering skills to use one of the SiLabs devices. I have hand-wired prototypes with them in dead-bug mode but good magnification and a steady hand are essential. I probably have a few lying around if you want one or two to play with. I would need to check exactly which versions I have.

The supply current is about 15mA at 2.7 to 5.5V. A small microcontroller might add a few more mA.

Reply to
jrwalliker

There are several ICs designed for something similar. I have, or had (I?m not sure where they are) a couple of cheap ?Chinese? radios someone gave me which were about the size of a match box. They had a couple of buttons to control the volume to a pair of ear phones and a couple to scan. FM only. I think the ear phone cable doubled as the antenna. I used then while walking before I bought an iPod.

The case was clearish plastic and, as I recall, there was only one IC and a few support components inside- plus the batteries.

I saw similar ones on sale for a few pounds.

Considering the price/simplicity etc, the performance wasn?t bad- certainly good enough for casual listening while walking etc.

The only niggle, you had to scan through stations to find the one you wanted, although I think I remained tuned to the last one used when turned off and back on.

Try a google for ?single ic fm receiver?.

Reply to
Brian Reay
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Cool ... and that was another question answered. ;-)

Thanks for the explanation. What sort of diameter are these loops do you know please and are they directional?

<snip>

Understood.

I'm not bad (been doing it for 50+ years) and it's more the eyes than the hands / iron as such. ;-)

I hear you John.

You are very kind. I have a straight linear tunable mini FM radio kit on the way so I'll check that out first.

So 3 x AA or a 3.7V Lipo should power it ok.

Cheers, T i m

Reply to
T i m

Whatever your original motivation, you nevertheless have passed the necessary qualification to develop your interests (and your project) further, and are to be encouraged to do so.

Reply to
Gareth Evans
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I also found this:

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Looks like it also needs some sort of microcontroller.

Cheers, T i m

Reply to
T i m

There is no elitism. _ A L L _ without exception are encouraged to study for the qualifying exams and to take an interest in electronics.

Perhaps there is a misuse of language here, with elitism being equivocated with qualified?

For, example, your local GP is not being elitist if he does not treat as equal someone whose only medical skill is to apply a Bandaid.

Reply to
Gareth Evans

What part of 'getting though an exam' and having no actual interest or skill in something don't you get?

I was an IT instructor for 7 years (CNI, MCT and A+CT) so have seen my share of those who are only interested in becoming 'paper engineers' as a means to an end, like all those who get degrees in subjects they have no interest in but that add a notch on their CV.

People forget, people never understood in the first place and many can pass a multiple choice exam without knowing the subject (a mate has passed 50 without knowing the subject on many of them[1]).

So a bit of paper can mean nothing and someone without a bit of paper isn't necessarily incompetent.

Cheers, T i m

[1] He 'tested' many of the professional electronic exams to make sure they ran ok etc and generally passed, even if they were on subjects that he had little knowledge of / on.
Reply to
T i m

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