Hello,
We are looking for a UHF amplifier (430-440MHz) for a transceiver to go from 10 mW to ~ 75W. Most of the amps were are funding require a much stronger input power than we can do. Note, it's a transceiver, so we want to be able to receive through the system as well. This is for half duplex satellite communication using a USRP radio.
Do you have any suggested amps?
Thanks,
--James, KF6RFX
James, I do not see any amps that would meet your requirements. There are several intermediate types that would boost the 10mw@430mhz to enable you to use this low power driving another PA after that to meet 75watts output. It seems that you should invest in a "normal" mobile or handheld xcvr that would come closer to what you are trying to accomplish. Go to Mirage amps website for some specs on amplifiers to get a feel for what is commercially available. 73, Dee, NB2F
-----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of James Cutler Sent: Wednesday, September 21, 2011 11:04 AM To: [email protected] Subject: [amsat-bb] Amplifier Suggestions?
Hello,
We are looking for a UHF amplifier (430-440MHz) for a transceiver to go from 10 mW to ~ 75W. Most of the amps were are funding require a much stronger input power than we can do. Note, it's a transceiver, so we want to be able to receive through the system as well. This is for half duplex satellite communication using a USRP radio.
Do you have any suggested amps?
Thanks,
--James, KF6RFX _______________________________________________ Sent via [email protected]. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
Hi James.
That is a lot of gain. 10mW to 75W is around 38dB. If I had this as a problem, I would consider putting two amplifiers together.
For example http://www.mirageamp.com/pdffiles/D-1010-N.pdf
But include a small amplifier 'brick' to get the drive up from 10mW. Perhaps the M57721M from RF parts in California. 10mW in and 7 Watts out.
Of course with just 10mW input, your amp will not automatically switch from RX to TX. - Best to switch manually and not with RF anyway.
Second choice would be to make an amp from scratch. - A quick look at RF parts again shows 50mW to 60 Watts is available in a single device. - RA07H4047M. cost is $23 but then a box and some relays and a LPF will be much more than that.
Thanks
David G0MRF
-----Original Message----- From: James Cutler [email protected] To: amsat-bb [email protected] Sent: Wed, 21 Sep 2011 17:32 Subject: [amsat-bb] Amplifier Suggestions?
Hello,
We are looking for a UHF amplifier (430-440MHz) for a transceiver to go from 10 mW to ~ 75W. Most of the amps were are funding require a much stronger input power than we can do. Note, it's a transceiver, so we want to be able to receive through the system as well. This is for half duplex satellite communication using a USRP radio.
Do you have any suggested amps?
Thanks,
--James, KF6RFX _______________________________________________ Sent via [email protected]. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
----- Original Message ----- From: "James Cutler" [email protected] To: [email protected] Sent: Wednesday, September 21, 2011 5:04 PM Subject: [amsat-bb] Amplifier Suggestions?
Hello,
We are looking for a UHF amplifier (430-440MHz) for a transceiver to go from 10 mW to ~ 75W. Most of the amps were are funding require a much stronger input power than we can do. Note, it's a transceiver, so we want to be able to receive through the system as well. This is for half duplex satellite communication using a USRP radio.
Do you have any suggested amps?
Thanks,
--James, KF6RFX
Hi James, KF6RFX
75 / 0.01 watt = 7500 time in power or 39 dB in power gain and no commercial RF amplifier in 70 cm is available to supply such high power gain.
Since you want to be able to receive as well through the system then to add a postamplifier that would boost the 10 mW to say 5 watt and use this low power to drive a 75 watt PA it became complicated because of relay switching the same tranceiver between RX to TX
73" de
i8CVS Domenico
James, Check out www.rfparts.com They have several low power amps, 10mw to 7 W most likely you will need two amps to get to the 75 watt level Select one that is class AB & use an attenuator in between amps. Art, KC6UQH
-----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of James Cutler Sent: Wednesday, September 21, 2011 8:04 AM To: [email protected] Subject: [amsat-bb] Amplifier Suggestions?
Hello,
We are looking for a UHF amplifier (430-440MHz) for a transceiver to go from 10 mW to ~ 75W. Most of the amps were are funding require a much stronger input power than we can do. Note, it's a transceiver, so we want to be able to receive through the system as well. This is for half duplex satellite communication using a USRP radio.
Do you have any suggested amps?
Thanks,
--James, KF6RFX _______________________________________________ Sent via [email protected]. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
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participants (5)
-
Art McBride -
Dee -
g0mrf＠aol.com -
i8cvs -
James Cutler