Swedish Microwave Triple band Ka LNB - Suitable feedhorn- Advice needed

[Joolz]

I picked up this triple band - Ka band Lnb super cheap on ebay. Can someone recommend what feedhorn (moded or DIY) to pair this with to get going?

Thanks

Joolz

 

[dreamsat]

Offset or parabolic antenna?
Linear or circular or both?
Is the waveguide output on the LNB WR 42?
It has an external 10 MHz reference. You still have to provide that too. I would say it gets a little complicated.

 

[Joolz]

I have both types of dishs but think I would start with a 1.2 offset -
This would be my first experiments in Ka Band so happy to swap feedhorn or insert a dielectric plate as needed.
Yes the waveguide looks to be WR42
On this unit it appears to have auto switching between internal ref and external

 

[s-band]

For wide band on an offset dish I use Patriot feeds. I've never had great performance using the diplexer and circular polariser outside its design range (bands B & C, I think).

Top, with diplexer & polariser. Bottom with circular guide to rectangular adapter.


Left to right:
Viasat & Polariser which was poor on the 0.8 f/d offset and difficult to interface the input guide.
Gilat band B with polariser which works well with a round to rectangular adapter on the offset dish and is OK 17.2-21.2GHz (the band D Gilat is not good at lower frequncies.)
Patriot feed
Patriot round to rectangular adapter (Wanted: another one of these)
Scientific Atlanta full Ka feed for PF dishes (can't find pic of feed end)


Patriot feed with home made 17-27GHz LNA on Prodelin feed mount. The feed appears to work well over the whole range.


9E with Patriot linear feed showing band B and EDRS at the top

I use a Gilat AN8024 for 17.7-21.5GHz with its supplied feed on the offset dish.

It has an external 10 MHz reference. You still have to provide that too.

The SMW ones have an internal 10MHz ref and auto switch if fed via the coax. I use Global Invacom ones but that sometimes appear on Ebay. Here's another brand DC Injector - Roks. Use with a 10MHz disciplined source or OCXO/TCXO.

 

[dreamsat]

I use the Gilat Depolarizer. I made a feed for parabolic antennas myself. I use the original transition from the Gilat LNBs for square wave output. Unfortunately, the part has to be removed from the rest of the larger housing in a lengthy procedure. Then you have the optimal adaptation. When I didn't have the Gilat yet, I worked with transitions from rectangle to round from Syria.

 

[Channel Hopper]

I picked up this triple band - Ka band Lnb super cheap on ebay. Can someone recommend what feedhorn (moded or DIY) to pair this with to get going?

Thanks

Joolz

View attachment 160626

You will need a matched feed to the frequencies you want to receive, and something that moves the unit between the polarities available.

Do you have a reliable Ka band reflector on the dish you hope to bolt it on to ?

What are the extremes of arc you can get at your location ?

 

[Joolz]

Looking to reuse an old Ka band from a Satellite Internet system and rotate by hand for now. The dish I have is a solid aluminium reflector, not sure if the mesh on a 1.2 CM is suitable. Visable arc is 53E to 63W but not from the same location!

 

[John]

Looking to reuse an old Ka band from a Satellite Internet system and rotate by hand for now. The dish I have is a solid aluminium reflector, not sure if the mesh on a 1.2 CM is suitable. Visable arc is 53E to 63W but not from the same location!

Personally speaking from experimental experience i would opt for a solid reflector - i use an Offset 1.2mtr Gibertini OP125L and a PF 2.2mtr Elite Antennas .
The 1.2m Gibby was bought years ago when some appeared at the right price, todays market shows much higher prices. Spending time and effort on accurate reflector installation for maximum rx efficiency on Ka is a must as well as accurate antenna pointing on Ka... Iv'e found my 1.2Gibby to be a very good performer.
There are professional Ka reflectors available sometimes on the net such as what @s-band uses but do not appear very often.
The SMW Ka lnb is a very nice unit for the bands that it covers but in this present day the services across those bands covered has reduced quite a lot from a few years ago.

 

[Channel Hopper]

Personally speaking from experimental experience i would opt for a solid reflector - i use an Offset 1.2mtr Gibertini OP125L and a PF 2.2mtr Elite Antennas .
The 1.2m Gibby was bought years ago when some appeared at the right price, todays market shows much higher prices. Spending time and effort on accurate reflector installation for maximum rx efficiency on Ka is a must as well as accurate antenna pointing on Ka... Iv'e found my 1.2Gibby to be a very good performer.
There are professional Ka reflectors available sometimes on the net such as what @s-band uses but do not appear very often.
The SMW Ka lnb is a very nice unit for the bands that it covers but in this present day the services across those bands covered has reduced quite a lot from a few years ago.

There are Viasat dishes for the Tooway service that appear on Ebay quite often, 90 cms and solid, though you will have to adapt a feed clamp to bolt onto the twin boom arm. For example

Via sat Dish And LNB | eBay

 

[Captain Jack]

I had that dish and was advertised here at some point but threw it in the skip since no-one wanted it.

 

[Channel Hopper]

I had that dish and was advertised here at some point but threw it in the skip since no-one wanted it.

The dish I linked to upthread is back up, complete with ODU and mounting bracketry