ozjohn

My latest penny. Not a rare date but but a nice example.

Yes I met Small when I was working at Sydney Uni. Small signal analysis is where you linearize a nonlinear transfer function around an operating point and is much used in electronic circuit design. I can also remember Goodmans suggesting that you mounted speakers in a concrete column. I have never seen any analysis of this but I suspect it would involve circular harmonics leading to Bessel's partial differential equations . Any relation of small signal to Richard Small is incidental as small signal analysis was used mainly in electronic circuit design to accommodate the non linear nature of vacuum tubes, FETs and BJTs. I'm afraid my audio is entirely shop brought with a Denon AVR X250BT 5.1 tuner amp and Wharfedale Alantic SE Series speakers 2 AT-400 SE and 2 AT200 SE. The Denon employs a white noise source to balance the speakers but does not support a microphone like the earlier Denon I had so I use a sound level app on my phone that seems to deliver reasonable results. I changed the earlier Denon as it did not support 4k HDMI. Earlier on in my career I worked at the MO Valve company where they made the KT 88 and KT 66 tubes. not realizing that they would be sought after today by some audio buffs who want to chase the Vacuum tube sound.

Hot Cross buns one a penny two a penny.

Thiele, A. N., "Loudspeakers in Vented Boxes: Parts I and II," J. Audio Engineering Soc., Vol. 19, No. 5, May 1971, pp. 382–392 (Reprinted from The above paper may be of interest if you are technically minded. It describes the design of bass reflex enclosures using second order control theory. I think audio reproduction has been revolutionised in recent years by the use of adaptive equalisers in tuner amplifiers where the response of the venue is scanned and the frequency response of the system adjusted accordingly. Using this very ordinary speaker systems can produce high quality results. I first saw this demonstrated when I was a student where students had to present a project as part of their course work to their fellow students and academics.

Sorry about the 1976 error a silly typo.

Check out this 1976 sixpence on Ebayhttps://www.ebay.co.uk/itm/1917-Great-Britain-6-Pence-PCGS-MS-66-Sixpence/173568759924?hash=item2869811874:g:eIsAAOSw9w1btBPg and PCGS https://www.pcgs.com/cert/34024776 It's nothing on ypur one.

Like the other posts I have difficulty in grading early George IV silver coins. When all else fails I suggest examination of the milling as that always seems to be deeply struck and an early indication of wear.

https://theassayoffice.com/tarnish_labexpert Food for thought. However my major concern is not so much the slabbing process more the inconsistencies of the grading outcomes for some coins. Always buy the coin not the assigned grade.

11/9 instead of 9/11? Also the numbers used for the US emergency telephone service.

I’m wondering if this coin is a fake of a fake. Most posts point to the obverse of the coin not being right. Although when I first saw the coin I thought it didn’t look quite right it was the crooked I in the QVI in the garter on the reverse that convinced me it wasn’t kosher.I checked this against the illustration in the fakes post in these forums and on examination of the original photo of the fake in the fakes post looked much more convincing than the example in the EBay listing.

https://www.ebay.co.uk/itm/Edward-V11-A-UNC-1905-Half-Crown/265082338390?hash=item3db8237c56:g:YvoAAOSwxCVgR2La This halfcrown has the wonky I in the QVI on the reverse that indicates it maybe a fake. What does everyone else think?. I hope know one is taken taken in by it.

https://www.numismaticnews.net/world-coins/fluorescent-light-coin-examinations

Try IfanView 64 or 32 which ha a resizing function.

Very nice. Large coins such as crowns collect surface marks due to their extra weight. Your coin is better than most of the 1/2 crowns graded Ef/g EF. Also the leaves on the reverse are much better minted than most halfcrowns of a similar grade.

EBay charges 10% GST on goods going to Australia and should not be charging VAT on exports from the UK.My advice for buying overseas coins from Australia is to buy from the seller’s site not EBAY if possible . You may be charged the UK VAT, which should not be levied but you will most probably avoid the Australian GST.

Hi Vicky, Here's a close up of the effected area. There seems to be a line through the center of the indentation that looks like it could be a metal flaw. There doesn't seem to be any pitting that you would expect with corrosion. Regards, Oz

A 1931 florin I have. I would like your opinion. If it a mint error or damage from circulation. All are appreciated. It has to be said that the milling is very good

Hi Blakeyboy, I cannot remember if I said this before. With the remaining seeds boil a jug of hot water and pour on the seeds and let soak over night. Then plant as normal. If you need some more I can harvest form this year's growth when they are ripe.. At present I am trying to pollinate a vanilla orchid I have. It grows like mad and producing a lot of flowers but pollinating it is a skill I have yet to learn. Regards, Ozjohn

Hi Blakeyboy, Did you receive the second envolope containg some dwarf poinciana seeds? Good to hear the poinciana seeds are going well. Ozjohn.

Messy perhaps but the carpet of spent blue flowers are a sight to behold.

Poinciana tree, delonix regia from Madagascar and even more spectacular than the jacaranda. It thrives in Queensland but not in Sydney as it is tropical in its requirements. I have seen them flowering in Egypt and often you can see them in the background in the TV series Death in Paradise. These trees flower in December.

Yes a spectacular tree native to Brazil widely planted around the world. I've seen them growing in LA and Spain as well. Grafton, NSW holds a Jacaranda Festival every year in November I'm sure they are grown in South Africa.

Photo of a Jacaranda tree taken a week or so ago at Laidley Qld. Jacarandas flower in Oct/November and mark the start of the exam period at High Schools and Universities.

Received the 1920 halfcrown graded by PCGS as AU detail cleaned. On examination there is no obvious sign of cleaning and in hand has reasonable luster. IMO the coin seems trouble free.

I agree flatbed scanners tend to make the high points appear to be flatter than they are also the lustre of the coin is not captured. Having said that I find it very hard to get a good image with a camera and as a result mostly use a scanner. Any insights on taking a good coin pictures would be appreciated. I've tried natural lighting and LEDs but the results are variable. I think getting the lighting right is critical for good coin photography.