I've noticed comments about "degutting" electrolytic capacitors, etc. I am coming back home to valve radios after about 50 odd years away from them - in my youth - and have a great deal of trouble trying to come to terms with modern electrolytic cap voltages. Best I can see is 115V and yet in the past, these things were rated at above 500 volts. Am I dreaming, - or have I lost it? - don't answer anyone, but it is becoming really hard to source caps that cater for HV on valve radios. Looking for help here guys.

The common voltages currently are 450V 500V and 600V.

The main danger is that virtually none of them, carry a surge volt rating. Surge volts are extremely important with filament, metal and silicon diode rectifiers, used with heater valves.

There are a few suppliers, seeing that you are in Qld goto EVATCO Rosewood. They have a website.

The Yanks tend to "re-stuff" electrolytics ..... I rarely bother

Marc

I agree with Marc, & don't bother to re-stuff the electros, just leave them there disconnected & mount your newies under the chassis.
I have purchased Caps both poly & Electro from Steve at http://www.goznet.com/index.html. When buying a quantity prices are very good. I stick to 600/650v where possible even if the original was only 450v for a bit of headway, touch wood... (my AWA R82 next to me! none have ever failed.
Regards Paul

Looks like his website has changed to http://www.radiorevivalparts.com/.

I've done the "two caps in series" trick to get higher voltage rating. This also answers the problem if the original cap was a small μF value, and all I have on hand are at least twice the μF and not enough voltage. The amount of μF is important for tube rectifiers, they have a fairly low max pulse current rating compared to soild state diodes. The bigger the μF, the bigger the max pulse current. (You can use bigger μF caps further downstream after usually 1K resistors in the B+ circuits for the RF and IF and audio driver circuits, the resistor limits the max pulse.) To be sure the voltage splits evenly across both caps in series, I use a pair of the same value and voltage rating (like 250V, to get up to 500V, and the result of the entire circuit is half the μF of each cap), and I add across each cap a resistor of around 330K half watt. This helps swamp out any internal leakage of a good modern cap, and divides the B+ voltage evenly on each cap. Be aware that the shell of the cap closer to the B+ will be at half B+ voltage to ground, so take care it doesn't short to the chassis or your hands. There's usually enough room below deck in the chassis to mount a terminal strip or such for this.

You can be guided by what is actually in the radio's & I have seen the inside of quite a lot.

The most common (max.) used voltage rating here was 525 Surge Volts (SV) Due to reliability issues especially with the (lack of) quality of some 450V types I will not go below 500V with filament rectifiers like 80 /5Y3 with B+ around 250V.

Heater rectifiers do not produce the same surge and there are filament rectifiers with cathode sleeves that also do not produce large surges.

There are exeptions, there are some PYE receivers that run the maximum volts on 6V6 and will need 600V types as do HMV that run 807 This does not have a huge voltage on the 807 but it draws 73mA. If it goes off line there will be a large increase in voltage, which is likely why it specifies a 600V SV cap. as the first filter.

There is debate about using a voltage divider across the filter cap's in series. However, my OS1 Oscilloscope has two in series for the EHT and they have 500K resistors across them (900V).

I really cannot see an issue. Now that we have suggested suppliers & methods that will get results.

Marc

Doug and Marc I carry all electros 350 / 500 volt plus!! they are better than 84 milliamp-- ripple current , they will not die.

Yes it is getting hard for Joe average collector to get all caps be it 630 volt pollies our range all axials ---- ( ive 19 types ) and the electros ive 15 types -- 500 volters are - 8/ 10. 16/ 20/ 22/ 33 μF at 500 volt axial all for not far more than $2.50 ea !

So long as the ranges are supported il keep carrying the lines and broadening the ranges - but we rarely see orders - which is really strange, for the sort of quality that we have, ''and for a paupers purse'' !!!!!

( nothing ive got is going to break the bank ).

Yes you find it all hear ( and I don't charge gst - I'm a total non believer in it ) and I post same hour on the same day.

We have in advance of now 85 lines -----the latest one is we had clips made hold the back boards onto the radios , metal fold clips with the screws - again we were asked for them for years, the moment we had em made there was nobody home for them? = really strange eh !

WEB SITE IS THUS
http://www.radiorevivalparts.com/.
Steve

PS ---we never close --- we are open 24/ 7 365 days a year.
thanks !

Steve, I think it would be useful to put a link to your new site on your old site. Either that or point the old URL to the new one.

If your old website can handle it, a '302 Redirect' is best as it will transfer the weight your old site has in the big search engines to the new site.

The new site looks good.

Steve: Apart from advertising availability. Issues that I have noted are along the line of the young not being interested, in the old technology and no one other than those in some Clubs, passing on the knowledge.

A large proportion of modern electronics is obsolete before it gets out of the factory and is often not worth fixing even if it could be.

That is wide spread even in other areas. I recently had a brushcutter come in, virtually new $97 Not designed to be fixed. It would take an hour just to pull it to bits & reassemble $ per hour.

With fixing Valve & early Transistor stuff the fixers are a dissapearing. In my town I believe that I am one of less than a hand full that can fix valve stuff and requests are coming in from over a 100Km away, which clearly suggests, other towns have the same issues.

I have taught some collectors here the basics of getting valve sets working and I now only see some of them when a really nasty set is procured.

Marc

Marc I believe that all the doom and gloom they speak of about the old industries its not correct , it broadcasts a far greater decline; than is really evident ))) no I think they are getting it all radically wrong !

Look at it now economic doom, thats real 70% of people lost half their super with the downturn etc since 2008 !

BUT !!! I reckon one real good thing is going to come out of all this, over the next 10 years I reckon there will be a boom in radio restoration etc ,& the hobby of ''lets build something that sings!!!

I will -- tell you why!! ( I ran this theory by a financial advisor and big business guy here in Perth) , he said by fugg u right !

We got million's of the second wave of baby boomer's retiring like from 2 years back to say , over the next 6 + years - acres of them !

Now unlike the lot that retired 15/ 20 years back , this lot does not have 35k to race out and buy MGB's etc flash toys for retirement !

Most have lost a lot of their coin, so a vast percentage will be looking for something a hell of a lot cheaper to entertain themselves with in the twilight years. What can they all relate to ? --------Radio is one item that comes to mind !

New generation Marc, no they wont pick it up, maybe 1 in 1000 will,,, but they are new age Y generation = ( why would u bother ) lol ! largely they have no conception of the worlds very existence, prior to the last 25 years !

No)))) Radios no good to them - hey they think eggs Benedict is an Italian gangster! - they got no idea ! so its no good setting up shop near a Uni campus with like 90k of old radio gear , they'd reckon they took a wrong turn and arrived at a Museum !

I think we will be safe for a few years yet - the generation retiring now are all looking for something ''affordable to do. '' I'm actually seeing a bit of it starting to happen now , ive got 3 new customers from that ''new pot of retires''

True---- we will have to educate a few of this younger generation to carry the flag'' after we are gone !
( I intend to check out, in around 55 years time)

Keeping radio alive and having to rely on the present day young ''robot generation '',,,that's a task in itself - they can't hold a candle to any of us, in the way of knowledge - We have been decades in radio! I guess we just must hope they carry the flag onwards - and not let it die !


Web page my old ones dead)))) I don't know how to update, I'm not ''Julius Sumner Miller'' too hard for me the old one ! I don't get into the web page thing - I can barely stand email, I loath pc's!

They are just an electric typewriter to me !! - I get people to do my updates, when I have time and spare coin - I got no intention learning more about pc's no no no no way lol !

Radio will live on, I think we will see a resurgence in the hobby restoration side of it all - yes I think so - its all in a lull at the present , via a combination of many factors , yet I think we will get over that hump !

Steve

You are right about the Baby Boomers retiring. I am seeing that now. I am looking like joining them as the body is already in strife.

With a disability and older age discrimination, regarless of qualifications no one wants you

I see plenty of retired people at the Mens shed that are at loose ends. I am in danger of getting the Presidents job there temporarily. So there might be some radical changes there if that happens.

I still see issues motivating the young, & finding them to train. There are a majority, in shools, that just don't want to learn and will be in for a rude awakening; When they leave shool.

Marc

I guess it can sometimes feel like one is being negative when looking ahead but there is an element of truth in all that has been said here.

To keep this thread on track for a second, one of the problem with obtaining components suitable for vintage radios is the fact that our hobby simply isn't big enough in terms of numbers of people to warrant component manufacturers making things like potentiometers, tuning gangs and condensers in values that suit the operating requiement of valve radios. What is happening in reality is that we are relying on the fact that we are buying from manufacturers that make these things for larger markets like Great Britain and the US, where there's a few hundred thousand people like us rather than a few thousand.

I've often thought of the poibilities of home-making items like switched 500k potentiometers for those needing new volume controls but then I think of what might have happened to the pressing and stamping equipment that Australia's resistor manufacturers once used. Equipment like that woul be essential for starting a small scale supply business.

As for the attitudes of Gen Y, it's easy to blame the kids themselves but it is not always justified. Kids pretty much adapt to their surroundings. If they are not brought up in an environment where things are appreciated and repaired rather thn being thrown way and replaced it is understandable that they will not sympathise with what we are trying to achieve. We are all driven by the demands of the corproate sector in this regard. Everything from motor cars to computers to the brackets that hold our rolls of toilet paper to the wall are designed to last no more than seven years - and often either look out of date or become irrelevant well before that time expires.

Brad you are right in what you say - yes in Aussie just over 3200 in radio in & out of clubs, then you have hams , the people in the guitar stuff, which is quiet a few then contacts in wireless institute .

All up ive got over 6000 addies radio related people that do use our type of gear , but some are barely 3 items a year people .

The core radio people ''active'' is just on 2800 nation wide , yes if you combine yanks and the poms its 100's of thousands , we are almost - non descriptive in numbers by comparison!

I found 2006 to 2009 numbers were diminishing , however when I asked all clubs recently how many members they have - the numbers they gave me certainly were showing that it has come back, ever so slowly but there is some of the new pot of retirees coming into it for sure!

So she is certainly not a dead marine as yet!!! I think in 20 years we going to have grief unless the new generation says well ''lets look at this hobby stuff '' a certain amount will do of course - weather its enough to man all oars and row the good ship radio? ---------remains to be seen eh !

Two things for sure Marc is 125% right in respect to work hey try and get a job if your over 48 - it wont matter if you have 8 licenses & 40 years experience in 15 fields of work !

Nobody but Nobody wants you - hm they increased the retiring age to 67 ( I think they should have reversed it to 55 - I mean if nobodies going to give you a job at 53/ 55 then whats the point in prolonging the agony waiting for your super until age 67 ???? no point !)))

Hey in reality you got more chance of walking to the moon at age 54, than you have of getting an interview for a job !

WA here - its been in the paper 20 times people writing in oh I applied to 71 jobs I'm 52!!! nobody il give me a go - its almost a weekly event in the papers here - they cry we can't have discrimination? lol lol .......plenty of it going around in this state .......thats for sure !

Some new products coming soon Brad they are at factory at present being made new Back bars for the 1937/ 39 Astor mickey mouse and the 1940 model BP mickey mouse!

Age descrimination is a subject on its own. There are people in government jobs pretending to be doing something about descrimination. They actually should be saving us at least some money, by being on the dole themselves.

I note the job comment. We have one of those private job mobs here that is supposed to handle people with a disability. Wandered in recently & naturally they were not interested, full scale fob off.

Yet they had the audacity to show up at a function to promote disability services. Making out I assume. The should be taken out, for defrauding us.

Some even have the gall to ask you to do jobs voluntary, when they are not a "not for profit organisation".

Marc