Can you help with GB Machin phosphor cylinder number?

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honza
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Can you help with GB Machin phosphor cylinder number?

Post by honza »

Ahoj everyone!

I am trying to identify phosphor cylinder numbers on my GB Machins using a SG specialised catalogue.

I have a 1½p black cylinder 1 dot, making it SG U71 which should have a phosphor cylinder number of S2, L2, L4 or nothing.

Question 1: Are the letters S and L shown as well as the number?

Question 2; Are the phosphor numbers to be found next to row 18 unless otherwise stated?

My block has printed cylinder 1 dot next to row 18 and phosphor 2 (no S or L) next to row 19. Is this normal?
GB  U71 Cyl 1 dot ph cyl 2 opp row 19.jpg
Cheers,

Honza
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Re: Can you help with GB Machin phosphor cylinder number?

Post by honza »

No Machin experts on board?
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Re: Can you help with GB Machin phosphor cylinder number?

Post by Erinmania »

honza wrote: 10 Aug 2022 03:06 No Machin experts on board?
Hi Honza

I will have a go at answering your queries and I can be corrected when an "expert" comes along.

Q1.There or no S or L letters adjacent to the phosphor cylinder number. On the dot panes the small 2 measures 2mm
and the large 2 4mm high.

Q2. Initially on the OCP/PVA printings the phosphor cylinder number was unsynchronised. Meaning it could be found anywhere in the left hand margin. later they were synchronised to be in the box opposite row 18.Often though the phosphor cylinder number can be found displaced either upwards or downwards. Blocks can also be found with the large phos 2 approximately 41mm below the small 2. Such blocks are best collected in a block of 10.
The large phos 2 can also be be found inverted.

Q3.As the phosphor cylinder number "floats" it is not unusual to find it opposite row 19. It is one of several varieties to be found. Some might say the normal is to have no phosphor cylinder displayed but others might disagree.

I hope this is of some help to you.
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honza
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Re: Can you help with GB Machin phosphor cylinder number?

Post by honza »

Ahoj Erinmania!

Thank you for taking the trouble to try to help me.

If the letters (S and L) are not displayed on the sheets, what do they signify and how are they identifiable?

With other values I have seen it noted when the phosphor cylinder number is opposite row 19, but not with the 1½p value. Hence I thought it might be unusual.

Finally I do not understand your mention of two phosphor 2s of different sizes in different places. I missed any mention of this in the catalogue. Could you please explain further?

As usual your willingness to help is much appreciated.

Best wishes,

Honza
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Re: Can you help with GB Machin phosphor cylinder number?

Post by Erinmania »

Honza,

Q1. The S and L have no philatelic significance. These are letters added by catalogues and dealers to show that there are different sizes of the phosphor cylinder number in their listings.
If you have a ruler the small phosphor 2 (s2) will measure about 2mm in height whereas the larger phosphor 2 (L2) will measure 4mm approximately in height. If you have blocks of both the size difference becomes clear to the naked eye.

Q2. The phosphor number appearing opposite row 19 on the 1½p value may be more unusual than most blocks of this value but I would not think it would add that much more to the market value than a block with the phosphor cylinder opposite row 18. That said I am not a Machin specialist so it could be more valuable to one of them.

Q3. Cylinder blocks exist which have both a small phosphor 2 and a Large phosphor 2. The spacing between the two sizes of phosphor cylinder number is around 40/41 mm in distance. The large phosphor 2 is found approximately 41mm below the small phosphor 2. You do not normally find these 2 sizes on a cylinder block of 6 due to the fact that the phosphor cylinder number can "float". This variety is best collected in a cylinder block of 10.

Best wishes

Paul
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honza
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Re: Can you help with GB Machin phosphor cylinder number?

Post by honza »

Ahoj Paul1

Thank you for your further help. I hadn't seen explained that L meant LARGE and S meant SMALL. That clears up a lot.

You have been a great help,

Thank you,

Honza
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Re: Can you help with GB Machin phosphor cylinder number?

Post by Erinmania »

Honza

Where a phosphor cylinder number is displaced the catalogues will show a figure "showing the distance in millimetres between the base of the ink cylinder box and the base of the phosphor cylinder number." As your displacement is opposite row 19 this would be indicated by (-). If the displacement was above the ink cylinder box this would be indicated by a(+). The catalogues usually ignore any displacements of less than 20mm.

So once you have measured the distance between the base of the ink cylinder and the base of the small phosphor 2 you will have your answer. If it is (-)19mm or less it is classed as normal. If it measures (-) 20mm it is slightly unusual. It will not make you a rich man.
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Re: Can you help with GB Machin phosphor cylinder number?

Post by honza »

Ahoj Paul,

Thank you again for the further information.

The measurement is slightly over 20mm, so slightly unusual. That is all I wanted to know.

Best wishes again,

Honza
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Re: Can you help with GB Machin phosphor cylinder number?

Post by honza »

Ahoj again!

I have three more questions regarding Machin phosphor cylinder numbers:-

1. 7p Wales SG W23 is listed with phosphor number 31, but this is sideways on my copy. Is that normal?

2. 8p Wales SG W25 is listed with phosphor number 22, but this seems inverted on my copy. Is that normal?

3. 3½p centre-band Wales has a footnote that it is known without a phosphor cylinder number. How common are such?

Cheers,

Honza
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Re: Can you help with GB Machin phosphor cylinder number?

Post by Erinmania »

Honza

Answers to your questions.

!/ Phos cylinder 31 printed sideways is normal.
2/Phos cylinder 22 printed inverted is normal.
3/ On this issue the phos cylinder 20 is very very faint and may not be visible at all which would be normal. I assume you refer to the no dot ink cylinder block.

As to current market I can't help you.
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Re: Can you help with GB Machin phosphor cylinder number?

Post by honza »

Ahoj Paul,

Thank you again for another concise and helpful answer.

Much appreciated,

Honza
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