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Re: Stealth Microwave SM2325-47 Amplifier
Posted: Sun Jan 20, 2019 8:05 am
by radiogareth
Still available too, from the same chap, now with 'make offer'....although this is a -44 unit so not sure its suitable for 2.4 as-is....
https://www.ebay.co.uk/itm/EX-MOD-Steal ... ctupt=true
Maybe we could try a 'bulk deal' (group buy) to tempt him to shift stock???
Cheaper than the spectrain 30 watt amp
https://www.ebay.co.uk/i/223333016897?ul_noapp=true
Gareth
Re: Stealth Microwave SM2325-47 Amplifier
Posted: Sun Jan 20, 2019 9:45 am
by g8gtz
Hi Gareth,
These are SM1920-44LIPWF which means they are designed for 1920MHz with +44 dB (25 watts) out.
I have "tested" one on DATV on 2400MHz and they are not much good giving 5 watts out for 6.5amps at 12v in with 20 dB shoulders!
They could possibly be made to work properly by changing filters / isolators and probably devices - not a job for the faint hearted...
73
Noel - G8GTZ
Re: Stealth Microwave SM2325-47 Amplifier
Posted: Sun Jan 20, 2019 10:00 am
by G4GUO
If you are after a suitable amplifier for 2.4 GHz, Darren G1ERM ( muziku_ukizum on eBay) may have some he is willing to part with.
Re: Stealth Microwave SM2325-47 Amplifier
Posted: Sun Jan 27, 2019 10:41 am
by radiogareth
Just take the lid off one of these Stealth amps I have acquired, the PCB says 2327-s47lrf. An aftermarket sticker (all other external markings removed) says 60 watts.
Its has 5 stages and two finals of TPM2626-30.
I'm believing the home made label
Will show it some drive later and report back.
Gareth
Re: Stealth Microwave SM2325-47 Amplifier
Posted: Sun Jan 27, 2019 10:48 am
by G8GKQ
Take care. It won't need much drive - they've got between 40 and 50 dB gain.
Dave
Re: Stealth Microwave SM2325-47 Amplifier
Posted: Sun Jan 27, 2019 11:14 am
by radiogareth
Noted, I'll start at zero with my Pluto/Express DVB to be safe(er).
The wonderful world of surplus
Re: Stealth Microwave SM2325-47 Amplifier
Posted: Mon Jan 28, 2019 12:43 pm
by G1BVI
Gareth
The one I have is a 2527, which only requires -9db input for full output.
73
Nick
Re: Stealth Microwave SM2325-47 Amplifier
Posted: Mon Jan 28, 2019 1:09 pm
by g0mjw
Mine came with the first device burnt out. I removed it and bridged it so I now need just a few dBm to drive it. Normall you need an attenuator rather than an amplifier, but with Pluto and LimeSDR you will be OK I think.
Mike
Re: Stealth Microwave SM2325-47 Amplifier
Posted: Wed Feb 27, 2019 10:33 am
by tonyaxn
Just playing with a SM2527-44LFFV connected to my Portsdown on 2400.175 and giving 1.4W output by holding down the input level.
It seems to get quite warm ... has anyone experience of the heatsink requirements ?
Thanks
Tony G4AXN
Re: Stealth Microwave SM2325-47 Amplifier
Posted: Wed Feb 27, 2019 4:07 pm
by g0mjw
It will get hot even with the standard purple heatsink, You will need two fans on top. The power out is not the issue as they are class A. Indeed, more RF means less dissipated. Takes 10A or so at 12V (not 13.8! - another 20W to dissipate). Mine is a 50V version and is takes 18A continuously.
Assuming yours is dissipating 120W and you want a rise of no more then 30 degrees (or you will burn yourself) then 0.25 degrees per watt of heatsink should do.
Mike