How does rubidium time source work?
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A rubidium time source is slightly misnamed: fundamentally it is an extremely stable frequency source. Your FE-5650A, for example, produces a very accurate output such as 10 MHz. Electronics can…
September 2026
How to test a small two dish amateur interferometer: If I want to test a two dish interferometer by walking in front of the dishes holding a small 1420 MHz signal generator, what is the best way to do this?
Yes. A small 1420 MHz test transmitter can be a useful way of checking a two-dish interferometer, but there is one important complication: if you walk close to the dishes,…
Are side lobes same as interferometry fringes?
No. Side lobes and interferometry fringes are different things, although both arise from interference/diffraction effects. There is an important connection: the observed response of a two-dish interferometer is essentially the…
Does it matter how accurately 2 radio dishes are pointed at a sky object when used for interferometry, as long as time signal is perfect for both?
Yes. Pointing accuracy still matters in interferometry, even if the timing between the two receivers is perfect. The important distinction is: TIMING Determines whether the signals from the two dishes…
Can a tuned Yagi be used as feed on a dish?
A tuned Yagi can be used as the feed for a parabolic dish, including at 1420 MHz, but it is usually not the best choice. The important point is that…
Interferometry fringes on ezCon: If the dishes are moved closer together what will happen to fringes
INTERFEROMETRY - WHAT HAPPENS IF THE DISHES ARE MOVED CLOSER TOGETHER? DISH 1 DISH 2 \ / \ / \ / \ / |<------ BASELINE ---->| MOVE DISHES CLOSER TOGETHER…
New interferometry arrangement at LRO using 2 x KrakenRF Discovery dishes with KrakenRF Discovery hydrogen line feeds on both of them and Wilkinson combiner/divider to combine signals from both dishes
The new setup is the pair of dishes on wooden mount on right hand side of photograph below:
Effect of changing the pull-up resistor connecting the lock indicator pin on the rubidium 5650A time source DB-9 port to +5V supply from 4k7 to 20k on 13 September 2026
Voltages measured have changed to these new values: 2.865 V unlocked 0.264 V locked (Previously were 3.8 V and 1.001 V with 4k7 resistor)
If I make cantenna with overlapping pieces of metal sheeting, then how important is it to have electrical connection between pieces of metal?
If you mean a metal cantenna/waveguide assembled from several separate sheets or pieces, then yes—the electrical connection between the pieces is quite important, especially as frequency increases. The reason is…
Is there non-conductive aluminium tape?
Yes—but the terminology is a little confusing. Aluminium foil itself is always electrically conductive. What you can buy is aluminium tape with a non-conductive adhesive. In that case: If you…