Suitable amplifiers for the LimeSDR mini ?

The place to discuss the use of the LimeSDR Mini for amateur TV applications
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darrenrainer
Posts: 15
Joined: Thu Aug 09, 2018 12:40 pm

Suitable amplifiers for the LimeSDR mini ?

Post by darrenrainer » Tue Jan 08, 2019 1:46 pm

I am going to put together a Portsdown with the LimeSDR mini. I will probably be using it on Es'hail and 146Mhz. I have a 230Watt WCDMA amplifier for 2.4GHz which I purchased at the Flight refuelling rally so hopefully can drive that from the LimeSDR (10mW out ?). What would be a good amplifier to provide 1 or 2 watts out on 2M ?

Regards

Darren G4VTQ Ottery St. Mary, Devon

g8gtz
Posts: 1137
Joined: Wed Apr 07, 2010 6:26 pm

Re: Suitable amplifiers for the LimeSDR mini ?

Post by g8gtz » Tue Jan 08, 2019 5:17 pm

Hi Darren,

LimeSDR Mini and other bits posted today - should be with you tomorrow at the requested address :-)

Have a look at this wiki page https://wiki.batc.org.uk/146_MHz_amplifiers for 146 MHz amplifiers - both types are good and the RD series amplifiers really are that easy to build. I think the Mitsubishi bricks are still available - it might pay to look at MiniKits in Australia as they used to stock it.

Happy memories of the Tim Peake contact in Ottery and look forward to working you - we often come out that way when /p at Win Green / Bulbarrow / Mere although I guess you are the other side of the Stockland Hills. If you went / p up there you could work Adrian UVZ in Taunton and also Malcolm UHY in Torguay.

73
Noel - G8GTZ

g0mjw
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Joined: Sat Sep 20, 2014 9:15 am

Re: Suitable amplifiers for the LimeSDR mini ?

Post by g0mjw » Tue Jan 08, 2019 6:28 pm

The lime output is a little low so it will need an intermediate amplifier to drive one of the mitsubishi bricks - assuming you can find one. There are several available via EBay which are recommended elsewhere on the forum. E.g. for about £10 what is described as "10MHz-1.5GHz 32dB Gain 27dBm LNA Broadband RF power Amplifier Module HF VHF UHF" will cover 4m, 2m, 70cm, 23cm. Other ranges are available, e.g. there is a board that work up to 700MHz up to 35 dBm. The "27dBm" amplifiers will generate a few 10s of mW of DATV cleanly, which is all you need. It is important, whatever amplifier you use, to make sure the filtering is good. Ideally bandpass but at the very least low pass and the designs used with the Portsdown should work well once you have the lime-mini output raised to a similar level.

Mike

darrenrainer
Posts: 15
Joined: Thu Aug 09, 2018 12:40 pm

Re: Suitable amplifiers for the LimeSDR mini ?

Post by darrenrainer » Tue Jan 08, 2019 8:56 pm

Hi Noel and Mike,

Thank you both for the advice on the amplifiers. I look forward to getting the Portsdown up and running. Next problem is to pursuade the xyl that the 11 ele 2M beam I have isnt to big to go on the roof :D Im at the bottom of a hill in Ottery so not to good for ATV but at least I will be able to use Es'hail. Hopefully will try some portable ATV soon and get the other side of the hill.
73s
Darren

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