Here's some beautiful discrete component DSB VHF homebrew from John, VK3AJG:
A rocket built by a group of Danish space enthusiasts has successfully launched on a short flight high above its sea-based launch platform.
The non-profit organisation Copenhagen Suborbitals built the rocket for around £42,000. They hope to eventually fly a human on a suborbital flight to space using a beefed-up version of the rocket, which is just big enough for one person.
Their first launch attempt a year ago failed to achieve lift-off due to a malfunctioning hairdryer used as a heater inside the rocket.
But their second try on Friday was a success. A video of the flight can be viewed here.
In the video, the rocket can be seen lifting off from its launch pad on the Baltic Sea and soaring high into the sky amid cheers. "We're going supersonic!" someone is heard saying shortly after lift-off.
A few minutes later, the rocket is seen splashing down in the ocean.
Though the rocket itself seems to have performed well, the parachute meant to slow its return to Earth does not appear to have fully opened. "There has been mission anomalies – we are now analysing," someone says in the video.
It was not immediately clear how high the rocket flew. The goal was an altitude of about 15 kilometres.
But the launch team was clearly thrilled with the flight. "The joy is just so huge," Peter Madsen of Copenhagen Suborbitals told Denmark's TV 2, according to a Google translation.
"We've written a little piece of history," added Kristian von Bengtsen, also of Copenhagen Suborbitals.
OM Jason, NT7S, has been experiencing the kinds of workbench trials and tribulations faced by anyone who tries to create something new. But I think the radio gods are looking favorably on his efforts -- a recent QSO with W7ZOI is a very good omen:
-- Why no crystal filters? Crystal filters not considered because of cost in terms of design & parts. In addition the LC filters allowed the designers to provide passband tuning both easily and cheaply in the 2-B.
-- How did it stack up against other receivers of the era? The 2-B was better than anything else for sale except Collins receivers, which cost a great deal more. There was also the R390, which was available on the surplus market, but it frequently was not is good shape and again cost a lot more.
-- Who designed it? The 2-B was designed by several engineers, but principally it was both Milton Sullivan & Bob Drake.
-- Why the copper chassis? Bill was not sure on this point other than to say that the Cu was meant to keep corrosion of aluminum chassis components to a minimum. Later they use cadmium as in the R4C/T4XC combination. In a couple of instances the chassis was plated with chromium and these radios are very rare and expensive collector items.
-- How important was the 2-BQ multiplier? While this is a highly sought after item today not very many were sold with the 2-B or even the 2-C. Today these are very valuable and command prices well above their original list price.
-- Was dial parallax a problem considered in the design? Not really as the crystal calibrator was supposed to be used along with the lines on the main dial slide to indicate the exact frequency. Band to band variation was very good for the time at around 3kHz. Not bad for a press DDS VFO.
-- Does he still have a 2-B? YES! And he would not part with it for any amount of money.
-- How many were made? He was not sure about this, but did say that the receivers are numbered consecutively, so that by knowing the first 2-B and the first 2-C it’s a simple subtraction to find the numbers of each manufactured.
-- Was it a big seller for Drake? Yes, but the R4 line which had a longer run and therefore sold more. The TR-3, and TR-4 line was a big seller for many years until the Japanese cut into their market share.
-- The TR-7A was Drake’s last ham gear and now they manufacture only home and commercial satellite receivers. These sell well to commercial cable, dish network, lodge net, channel modulators, D-A converters. They are now located in Franklin OH.
-- No ham gear is made by Drake these days as it is all commercial receivers for the satellite TV/radio market. The R8 was their last ham receiver and it still sells well on the used market.
-- For replacement tubes look to http://www.tubesandmore.com/. The transmitting tubes, 6JB6’s, are particularly hard to find. Look for a substitute sweep tube that can be used in that circuit.
-- John M Cherry, John Covelli, WB4HFN and Evin Rolek K9SQG@aol.com host the Drake Forum every Dayton Hamvention run by. A good resource for repair is John Kriner, WB4HFN
-- Drake's web sites: http://www.n9bor.us/drake.htm & http://home.online.no/~
To preserve the parts on a 2-B, especially the cosmetic parts, keep it out of sun & don’t smoke. These parts are particularly had to find these days.
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