ozjohn

I had a look into the difference between the KT 66 and KT 88 tubes. The KT 88 was an older tube and of a higher power rating than the KT 66. KT 66s were probably used in domestic HiFi amps as 20 watts output power was deemed sufficient as the dynamic range of vinyl LPs was about 45 dB and with an average listening level of about 0.5 w to 1 w the headroom was sufficient to prevent excessive distortion. There were also a lot of power amps based on the Wireless World Williamson amplifier that delivered 10 w output power using EL 84 tubes in push pull. Most modern domestic HiFi amps are in excess of 50 w output power to accomodate the much increased potential dynamic range of 100 dB offered by CD and other digital streaming as the dynamic range is determined by the number of quantisation levels during digitisation rather than a voltage level or the distance a stylus can travel on a vinyl record.

My Grandfather had a pewter tankard with a glass bottom. On the glass bottom there was a picture of a man on the gallows and an inscription, "Good to the Last Drop."

Impressive setup. I'm afraid I like math approach. Yes the KT66 was the lower power tube while the KT 88 was a higher power device. KT stands for kinkless tetrode .

They both came from the same seller.

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.

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.

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.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.

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 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

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.

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.

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.