Documents Similar To Raytheon Amateur Tubes. Skip carousel. Hollow State Newsletter - Issue Raytheon Characteristic Data Chart. Tubes. Some sort of tube structure is required to keep the telescope optical If you look through the ads in any amateur astronomy magazine you will see lots of. line, the eighteenth of an inch in length, no less than one hundred and fifty tubes. In an inch long there would consequently be (18 × ) twenty-seven hundred.