How much should one invest in tools to get in the hobby/occasional business?
 

Assuming one has the technical knowledge and the space (I have neither yet), how much money should one invest in order to get a half decent lab that is good enough for repairing old(sih) radios either as an advanced hobbyist or an occasional part-time business (such as buying dead radios, repair and sell)?

And what tools do you think are necessary beyond a soldering station, multimeter, cables, etc?

Re: How much should one invest in tools to get in the hobby/occasional business?
 

My approach has always been to try to repair things first with basic equipment and only buy things when you really need them to do a job. Hopefully that bit of kit will then be useful in the future. However, even then you will still end up with things gathering dust as either technology or interests move on.
Pete

Re: How much should one invest in tools to get in the hobby/occasional business?
 

Test gear wise I'd buy in the following order:-

Multi-meter.
Signal Generator.
Scope
Megger

A valve tester would be way down the list.

I'd also build an electrolytic capacitor reformer.

Re: How much should one invest in tools to get in the hobby/occasional business?
 

The signal generator need not be posh at all, you can make a simple one, calibration is the issue. I would go for a cheap SDR (software defined radio) as a measuring device, something like an RSP1A will "see" almost anything RF wise in a radio. The joys of having modern tech available for servicing.

Re: How much should one invest in tools to get in the hobby/occasional business?
 

When it comes to how much to spend, it's obviously a highly personal decision. Some people get a lot of satisfaction from working with lots of top quality professional tools and instruments, and are prepared to pay accordingly. Others actually enjoy making do with minimal amounts of cheap or even downright poor quality tools. Everybody is different. See any of the threads discussing DMMs or soldering irons to see examples of this.

Re: How much should one invest in tools to get in the hobby/occasional business?
 

Apart from my DMM's most of my test equipment is second hand stuff which I could never have afforded when new. I did have to repair most of it when first acquired though and it's not that reliable.

Re: How much should one invest in tools to get in the hobby/occasional business?
 

A lot less than I have :) I like nice tools, I collect obsure and once-expensive test gear. But I'll be the first to admit I could manage with a lot less if I had to.

More seriously, the most important 'tool' is something you can't buy. A brain with experience.

Do not make the mistake of thinking that expensive test gear will always help you out. When started working with computers/digital electronics I read about this wonderful instrument, the logic analyser. I couldn't afford one as a schoolboy, but I thought it would have solved all my problems and made things so easy. Well, now I own 4 of them, and while there are times that I do 'need' one, it's rare. 99% of the faults I have, and indeed 99% of the faults in vintage radios, amplifiers, record players, tape recorders, etc can be found with a multimeter.

And you don't even need an expensive multimeter. While some people here love to have accurate instruments, I find that any cheap digital meter will do. You do not need to measure the valve electrode voltages to more than 2 significant figures most of the time, if not all of the time.

The main time you will need a calibrated signal generator when fixing a vintage radio is if somebody has been there before you and twiddled all the trimmers and cores. If the set is untouched it is very unlikely to need realignment to get some sort of reception.

Re: How much should one invest in tools to get in the hobby/occasional business?
 

After a multi-meter, the most useful item I have for fault diagnosis on domestic radios is a signal tracer/injector. It quickly enables me to discover whether the fault is in the audio stage, or the IF/RF stages, and to pinpoint where in each stage the fault/faults lie.

Of course, let's not overlook the other essential item - a datasheet, or at least a circuit ('schematic' in some countries).

Re: How much should one invest in tools to get in the hobby/occasional business?
 

My 'important equipment' list would be:

A DMM; a cheap £20 one from Farnell/RS will be good-enough.

A Digital Frequency Meter going up to a couple of hundred MHz. Again, surprisingly cheap.

A crystal-controlled calibration-oscillator [mine has 1Mhz, 100KHz, 25KHz and 10KHz outputs with harmonics]

A couple of decent power-supplies [I've got one that does 275V@100mA/6.3V@4A and another that does 2.5-30V@3A and another that's 10-15V@30A]

A Wattmeter and a 50-Ohm dummy-load.

A component-tester [the little 'Peak' ones are worth having]

Then a 'scope that goes to at least 20MHz, along with a set of suitable probes.

The above reflects my main interest in the RF/ham-radio side of the hobby; if your interest is predominantly audio then you might want an audio signal-generator and a power-meter designed for use with 4- and 8-Ohm loads.

Re: How much should one invest in tools to get in the hobby/occasional business?
 

Thanks all for your input.

Re: How much should one invest in tools to get in the hobby/occasional business?
 

Another piece of advice I've just thought of comes from a book on photography (don't worry, this is not going to go ridiculously off-topic) -- "The Lens Book" by Frances Schultz and Roger Hicks. They suggest that before buying lenses for your camera system you should think of the sort of photographs you take (or would like to take) and conversely those you have no interest in, and then work out what the ideal lenses for that are.

In the case of vintage radio, etc, repair, think of what you are interested in, and conversely what you have no interest in. If you are interested in audio amplifiers you might end up wanting a distortion meter If you are interested in domestic radio receivers, or amateur band transmitters, then you probably don't need one. If you are interested in vintage computers, particularly bit-serial machines, then you might want a logic analyser. Again, if you prefer domestic radios, you won't.

So my advice is to get a multimeter. I can't think of any branch of this hobby where you won't need that. It doesn't have to be expensive or fancy, a £20 no-name digital meter will be fine. Then get something you are interested in repairing, not too expensive or rare, if you are interested in radio then a 1960's or 1970's transistor receiver, or a slightly older valve one. Try to learn how to repair it and get it going. When you get stuck, ask here. It may be that life would be a lot easier with a certain other bit of test gear. If that keeps on being recomended then (and only then) do you consider getting it.

Re: How much should one invest in tools to get in the hobby/occasional business?
 

If you are wanting to repair vintage valve radios be aware that the voltages on service sheets were measured with by modern standards a low ohms per volt meter, i.e. an Avo 7. Measuring them with a modern DMM will give erroneous readings which might lead you astray until you have the experience to allow for what will be too high readings. Therefore on my list for you is an Avo 7. This topic has been discussed before on here.

Re: How much should one invest in tools to get in the hobby/occasional business?
 

Absolutely right about having a meter, with the right ohms/volt to work on valves, but...are there any half decent analogue meters around that aren't so bulky as an AVO? Many members bought the £9 analogue (20k/volt) meter that Maplin did just before they closed, but actually, something just a bit better would be nice if such a thing can be found.

B

Re: How much should one invest in tools to get in the hobby/occasional business?
 

Well now.... I've just looked at the service information for a couple of popular valve radios (available 'up top', I have bought the DVDs) -- the Bush DAC90A and the Philips 209U.

In neither case can I find voltage test values in the manufactuer's data. In the Trader Sheet, the former has the voltages measured with an AVO 7 (1000 ohms/volt) and the latter with a 20000 ohms/volt meter (like an AVO 8). Since it is relatively easy to reduce the sensitivity of a meter -- to make a modern DMM behave more like an AVO 7, my advice (to buy an inexpensive DMM) still stands.

Re: How much should one invest in tools to get in the hobby/occasional business?
 

I think you need to look again.

The manufacturer's sheet for the Bush DAC90A shows the voltages in a table on page 5.

The manufacturer's sheet for the Philips 209U shows the voltages in figures 7 and 8.

Re: How much should one invest in tools to get in the hobby/occasional business?
 

To get started, I'd probably say:

1. Multimeter (and pick up a second one as soon as you can)
2. Bench power supply
3. Oscilloscope
4. Bench speaker (and/or signal injector/tracer)
5. Self study

No need for expensive stuff - investing big money just adds pressure (though you should get some of the investment back if you have a change of direction). I've written loads about cheap multimeters - although I have several "posh" ones, the cheap ones get as much use. People will talk about possible safety issues with cheap meters, but restrict their use to low-energy bench use and you should be fine. Also understand that the biggest factor in multimeter safety is you, the user.

As to costs, cheap-but-good multimeters are around £20-30 each.

Bench power supplies are essential, but what people often forget to mention is that you need adjustable current limiting. Not all bench PSUs have that. Some sets have faults that are made worse by batteries or other types of power supplies - but if you can tell the PSU to not give any more than, say, 50mA, that'll save the output stages from further harm (germanium output transistors aren't impossible to source, but they're not getting any easier too!).

As with multimeters, two is ideal as some battery sets run from 2 separate supplies generated by the installed batteries.

Personally, I'd avoid new and cheap, and look for a classic Thurlby Thandar or Farnell unit - they often come up on the forum (many others are available too). They might need a bit of TLC, so perhaps look out for one that is described as fully restored and working. Expect to pay anything from zero to £100, perhaps. Alternatively, a bench PSU is a good DIY project that will teach you lots - I managed just fine for 20 years with homemade units.

Of course, if you're more into valve sets, then a lamp limiter is of more use, and is an easy DIY project. But what people forget to mention (again!) is that lamp limiters can work at DC too - so if you are into transistor sets, but don't have the PSU with adjustable current-limiting that I strongly recommend, then a suitable light bulb can be put in series. For example, a 12V, 1W lamp would take around 80mA in normal use, so might not be a bad choice for a 9V radio...

Oscilloscopes were once extremely expensive. As a result, they were beyond the means of a lot of repair workshops, so people had to learn to manage without. This is admirable, but like working in almost complete darkness. I'm lucky - I was given an oscilloscope when I was 16. It was quite a nice one too. It had a pretty major fault, but fixing that taught me a lot about how oscilloscopes work - this was a long time ago when 'scopes were still expensive, so I had a really strong incentive to persevere, and I'm glad I did! But as a result, it really helped me to understand what is going on in a circuit. Speaking as someone who's always had a 'scope by my side, I find it frustrating when I see older folk downplaying the usefulness of a 'scope - either on the job, or on forums - just because they had to struggle back in the day. Today, good second-hand 'scopes are cheap (few 10s of pounds) or sometimes free. Get one. Learn how to use it. Thank me later (you will, I promise ;)).

I wish people used bench speakers more - it saves so much time. I have one semi-permanently connected to me 'scope, but it gets used for many other applications. David mentioned signal tracers/injectors earlier, and this falls into much the same category - in fact, have a search, as he has written a lot about his experiences with his. A signal tracer (or speaker) means you can, for example, check to see if the fault is in the audio stages or the radio stages beforehand. I've lost count of the threads where someone asking for help has dived into a radio without knowing which it is. I mean - if your engine was misfiring, would you take the gearbox apart?

By "bench speaker", I just mean something that contains an amplifier. An old set of PC speakers will do, and will be cheap or free. But if you follow David's advice and build the Velleman unit he recommends (is it K7000?), then a powered speaker is basically part of that.

Finally, far more important than the gear is to read up and learn how stuff works. Having been on the vintage forums for more years than I care to mention, and also teaching engineers as my day job, I would say that this is the biggest hurdle for most people who are new to the hobby, and isn't one that can be fixed by throwing money at it! Based on appearances, many assume that a radio is simple, and while I can understand where that comes from, it simply isn't true. They are arguably almost as complicated as TV sets - it's just that TV sets contain more stuff - that stuff is mostly no more complicated than the stuff in a radio. Before anyone jumps on me, that's obviously a simplification to make a point - I've fixed TV sets and professional monitors for 30+ years - but the point remains. Learn how radios really work, and should you ever jump to TV sets, you'll be pleasantly surprised at how easy the transition is. At least, I was.

Please don't take this the wrong way, but if you're thinking of doing this as a bit of a sideline, be a bit careful with anything that has a mains plug on it. There's nothing more scary to experienced engineers than someone with little knowledge but a lot of confidence (Google "Dunning Kruger"). You don't want to be responsible for the consequences of getting something wrong - morally or financially - so it's really wise to stick to battery stuff at first. Fortunately I'm employed, but if I was to go freelance I'd definitely think about a similar sideline, but would spend a lot of time reading up on insurance and regulations first - I might have the technical knowledge, but freely admit that I have big gaps in those areas. Fortunately, lots of people here can give good advice.

Finally, speaking as someone who's workshop is a cellar with no natural light, I'd say that the environment you set yourself up in is the most important thing, secondary to the kit itself. It has to be safe. And warm and dry and cosy, and very well lit. And with controllable ventilation when soldering or using chemicals. Easy access to kettles and fridges is good, and a few creature comforts like a decent sound system and internet access is essential! Don't underestimate the amount of stuff you'll need to store there, and secondary storage (attic, garage, shed, etc) might be needed as your collection of "projects" grows. I have several hundred radios in the attic here (plus a lot of other junk), and I sometime have vivid nightmares about what might happen if the ceilings were to give way. Fortunately it's a Victorian build with decent timbers - I didn't dare put anything in the loft of my last house - a late '70s build with matchsticks for roofing timbers!

Good luck,

Mark

Re: How much should one invest in tools to get in the hobby/occasional business?
 

It's a bit like DIY. Get the basic tools, and you can do the basic jobs. More tools means you can do a greater range of jobs.
Buy other test equipment as you need it, then you can do more complex jobs. The trouble is you get to the stage where you think "I could do that if only I had such & such......

So do be careful, as your equipment may multiply!

There is an awful lot you can do with just a meter and a few hand tools.

Re: How much should one invest in tools to get in the hobby/occasional business?
 

Including a 'fridge in your workspace can be problematic from the point of view of getting badly timed invasions from the household, so if you're in an outbuilding the list could include a bolt for the inside of the door and a pair of walkie talkies. You can't control the outside world when really concentrating but i find i can ringfence it for as long as needed to prevent accidents and 'doh' moments.

Back to tools, i should really get a pair of those crocodile/alligator clip 'helping hands' things for tricky soldering etc.

Dave

Re: How much should one invest in tools to get in the hobby/occasional business?
 

The only extra to the standard iron and DVM would be an AF/RF sig gen and a basic scope. The RF sig gen for checking sensitivity and the AF for the audio stages. With a scope you can see amplitude etc and it can double up as a voltmeter.

Malcolm

Re: How much should one invest in tools to get in the hobby/occasional business?
 

There is a trade-off. How much of a hurry are you in? If you're patient and keep an eye open for good things turning up, you can pick up all you need and a good few luxuries for trivial amounts of money. If you want stuff right now, then it costs more.

Multimeter first, then keep your eyes open for sig gens, read up on what others have and why (there was a fairly recent thread where pretty much everything worth saying got said). Scope next, again keep eyes open. Then maybe a little portable L/C/R/ESR sort of meter.

Don't worry about getting things out of order, if that's the way bargains turn up.

There is no right answer.

David