24GHz Transverter

Microwave and up topics.
G0DJA
Posts: 94
Joined: Mon Sep 16, 2019 12:49 pm
Location: Bolsover

24GHz Transverter

Unread post by G0DJA »

I've taken a couple of pictures of the 24GHz transverter. It's been checked out and realigned on the current narrowband section of the band.
IMG_0054[1].JPG
IMG_0053[1].JPG
I need to remove the dish and re-solder the waveguide to the flange on the box.
Cheers - Dave (G0DJA)
G0DJA
Posts: 94
Joined: Mon Sep 16, 2019 12:49 pm
Location: Bolsover

Re: 24GHz Transverter

Unread post by G0DJA »

Just realized that I'd not taken a photo of the dish that's attached to the front.
IMG_0055[1].JPG
Cheers - Dave (G0DJA)
G0DJA
Posts: 94
Joined: Mon Sep 16, 2019 12:49 pm
Location: Bolsover

Re: 24GHz Transverter

Unread post by G0DJA »

I've removed the 'penny' feed and I think that whoever made the feed up miscalculated slightly.

The usual way to calculate the feed point is to measure the diameter (D) in cm and the depth (d), again in cm, of the dish then use the formula

Feed point (f) cm = D x D/16 x d

Since the diameter of the dish is 25cm and its depth is 6cm the focal point should be at 6.51cm (incidentally, this makes the f/D ratio of the dish 0.26 which isn't great but will have to do for now) but the waveguide only reaches to 6cm from the centre of the dish. So, when I unsolder the dodgy end I'll cut back the block behind the big flange and drill and tap a hole for a screw to hold it in place.

Unfortunately, all of the 24GHz beacons are a bit far away unless there is a really good opening, so I'll have to ask to see if one of the people with a lot more power available than I have with this set up can put up a signal for me to look for.
IMG_0057[1].JPG
IMG_0059[1].JPG
Cheers - Dave (G0DJA)
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