Pye Black Box resistors.

[Nukeybrown]

I'm having trouble understanding 2 resistors, I have the data sheet etc. The 2 I'm stuck on are

R8 2.2m ohms, only one I can find is rated 1 watt 10000v is this correct.

The other one which is the same on 2 parts of the circuit are

R9 and R11 I think they're showing as 57k but with what looks like a crucifix in front of them. This one I'm completely at a loss with.

I'm replacing all components onboard for new ones, and have managed on all other ones but these 2 have me stumped.

Any help greatly appreciated.

[AC/HL]

You appear to be using the Trader sheet. If you look at the bottom of the components list it explains that the value of R9 and 11 can be between 47 and 68k and are high stability. These days all resistors are more or less HS. Replace them with the same value you find fitted in yours. One watt resistors are a good physical size for old equipment, the others can be a bit small.

[Nukeybrown]

Thank you for that information. I've gone for 2W resistors as recommended by someone on forum. The issue with R9 and R11 is I couldnt find a resistor available that was 47k on the market. So was not sure which one to replace it with.

[Station X]

Originally Posted by Nukeybrown

The issue with R9 and R11 is I couldnt find a resistor available that was 47k on the market.

Unbelievable. 47k is a frequently used preferred value and easily obtainable.

[Nukeybrown]

Also the 2.2 resistor the only one I could find was 1w which I'm guessing should be fine. All others being replaced are 2w

[Station X]

You can replace any resistor with a higher power one, but it may be more expensive or cosmetically unacceptable compared with a resistor of the correct power rating. Modern resistors are physically smaller for the same power rating.

[Nukeybrown]

Both the 47k ones are reading 57.5k and 58.5

[Station X]

Replace them with whatever the colour code says. Presumably 47k, Yellow, Violet, Orange?

[Lucien Nunes]

Might I recommend the following resistor:
47k 2W at Cricklewood Electronics

Replacing resistors popular these days but is rarely necessary. In a typical record player or radio, there are a few circuit positions where it is good to have a decent accurate resistor and if it has drfited badly, replacement will improve performance. For true HiFi there might also be a small improvment in linearity and noise by upgrading certain old carbon comps to metal film. But as for replacing every resistor, many of them will work fine if they are within +/- 50% or more, and no benefit at all is gained by wholesale replacement.

[Nukeybrown]

They're showing green violet orange orange. Just checking as unsure if these are original or have been replaced with incorrect ones

I'm thinking more reliability rather than performance enhancement

The crickewood one you link is showing Diff bands

[Station X]

It's just an example of what a resistor looks like. They won't go to the trouble of photographing every resistor they stock.

Only change one component at a time, so if you make a mistake you'll know where it was.

[Nukeybrown]

I'm confused , the service sheet is saying 47k but the 2 that are in read 57.5 and 58.5 so do I put in 47k as per service sheet or 57k which is closer to the ones that are in?

[camallison]

Originally Posted by Nukeybrown

I'm confused , the service sheet is saying 47k but the 2 that are in read 57.5 and 58.5 so do I put in 47k as per service sheet or 57k which is closer to the ones that are in?

As Bill says, "If you look at the bottom of the components list it explains that the value of R9 and 11 can be between 47 and 68k and are high stability." So replace with the closest to what is in there at present.

Colin

[peter_sol]

It does not matter much about those values so long as they are equal
nothing wrong with 57.5k and 58.5k they were possibly both 56k and yours are within tolerance
Pye just used what they had in stock.

[Station X]

Originally Posted by Nukeybrown

They're showing green violet orange orange. Just checking as unsure if these are original or have been replaced with incorrect ones

That's 573k. Not very likely.

Could they be Green, Blue, Orange 56k?

The second orange may in fact be Gold indicating 5% tolerance.

They're still in tolerance after 50 or 60 years, so why not leave them alone?

[turretslug]

I'd be rather pleased to find ones that close after so long- whilst it can be wise to weed out badly drifted resistors, it's just making unnecessary work to blanket change things and runs the risk of introducing a fault.

[ms660]

Originally Posted by Nukeybrown

They're showing green violet orange orange. Just checking as unsure if these are original or have been replaced with incorrect ones

Green, Violet, Orange equates to 57k, 57k is what's shown in the Trader sheet, they are probably the originals, if they both read close to 57k then they will probably function ok.

If reliability is a concern then 56k close tolerance resistors should be ok.

Lawrence.

[Half a Mullard]

I have the PCL83 version, not sure if this is the same model as the OP

The resistors on mine are 57k ie green, violet, orange.

[Station X]

The resistors are still in tolerance, even though they're 57k. If the OP wants to change them he can use 56k with 1k in series.

[Hartley118]

Those resistor values sound reasonably well matched to me. I wouldn't mess with them. Could that second 'orange' band actually be salmon pink - the indicator of a high stability resistor?

Martin