I have had several FT 847 radios.Great low cost choice and works well with satpc32.However ,for just a few dollars More get a used IC910. Much better rx sens with a lower noise figure.Also REAL DNR circuitry.Make listening for long periods a pleasure,not so exhausting. Also if you compare the specs of the IC910 and IC 9100 uhf and vhf SECTIONS, you will see they are IDENTICAL!
jeff broughton
On 09/01/16 11:01, jeffory broughton wrote:
I have had several FT 847 radios.Great low cost choice and works well with satpc32.However ,for just a few dollars More get a used IC910. Much better rx sens with a lower noise figure.Also REAL DNR circuitry.Make listening for long periods a pleasure,not so exhausting. Also if you compare the specs of the IC910 and IC 9100 uhf and vhf SECTIONS, you will see they are IDENTICAL!
I wouldn't focus on noise figure at the receiver, unless you happen to have 1' of cable between the rig and your antenna. Instead, I'd put a bias-T-powered LNA at the antenna to preserve your SNR (Friis formula).
Having recently built a U310-based LNA, I can say that a single night's work of soldering and testing pays off well. Total parts cost was in the $5 range.
I plan to build a new LNA based on a pHEMT just for fun. Only a couple of bucks from Digikey. Why settle for 1.0dB when you can potentially get 0.25dB! :-)
--- Zach N0ZGO
AMSAT-BB Users..... Just so you know, many E-Mail Spam Filters send messagesthat have the title "No Subject" directly into the Spam Foldersince there are so many Phishing Scams that use messageswithout titles. So, if you want a lot of people to actually SEE your messages,then you always need to give them a TITLE. :-) 73, Bob K8BL
From: Zach Metzinger [email protected] To: [email protected] Sent: Thursday, September 1, 2016 12:17 PM Subject: Re: [amsat-bb] (no subject)
On 09/01/16 11:01, jeffory broughton wrote:
I have had several FT 847 radios.Great low cost choice and works well with satpc32.However ,for just a few dollars More get a used IC910. Much better rx sens with a lower noise figure.Also REAL DNR circuitry.Make listening for long periods a pleasure,not so exhausting. Also if you compare the specs of the IC910 and IC 9100 uhf and vhf SECTIONS, you will see they are IDENTICAL!
I wouldn't focus on noise figure at the receiver, unless you happen to have 1' of cable between the rig and your antenna. Instead, I'd put a bias-T-powered LNA at the antenna to preserve your SNR (Friis formula).
Having recently built a U310-based LNA, I can say that a single night's work of soldering and testing pays off well. Total parts cost was in the $5 range.
I plan to build a new LNA based on a pHEMT just for fun. Only a couple of bucks from Digikey. Why settle for 1.0dB when you can potentially get 0.25dB! :-)
--- Zach N0ZGO _______________________________________________ Sent via [email protected]. AMSAT-NA makes this open forum available to all interested persons worldwide without requiring membership. Opinions expressed are solely those of the author, and do not reflect the official views of AMSAT-NA. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb
On 9/1/2016 11:54 AM, R.T.Liddy wrote:
AMSAT-BB Users..... Just so you know, many E-Mail Spam Filters send messagesthat have the title "No Subject" directly into the Spam Foldersince there are so many Phishing Scams that use messageswithout titles. So, if you want a lot of people to actually SEE your messages,then you always need to give them a TITLE. :-) 73, Bob K8BL
me for one.
Zach - N0ZGO said (in part):
I plan to build a new LNA based on a pHEMT just for fun. Only a couple of bucks from Digikey. Why settle for 1.0dB when you can potentially get 0.25dB! :-)
Next step will be the tank of liquid nitrogen. How much lower can you go?
Jim Walls K6CCC
On 09/01/16 12:14, Jim Walls wrote:
Zach - N0ZGO said (in part):
I plan to build a new LNA based on a pHEMT just for fun. Only a couple of bucks from Digikey. Why settle for 1.0dB when you can potentially get 0.25dB! :-)
Next step will be the tank of liquid nitrogen. How much lower can you go?
*chuckle* Yep, "down the rabbit hole". N1BWT's noise paper is what got me started down this path in the first place...
--- Zach N0ZGO
On Thu, Sep 1, 2016 at 11:01 AM, jeffory broughton [email protected] wrote:
.However ,for just a few dollars More get a used IC910. Much better rx sens with a lower noise figure.Also REAL DNR circuitry.
Thank you for validating my recent acquisition. :-)
To get the Noise Reduction (and the auto notch filter) you have to have at least one UT-106 DSP module installed (you can have one each for Main and Sub bands). Mine has one but I'll probably snag another off eBay as they are pretty common (and much cheaper, for some reason, than the UT-102 voice synth).
participants (6)
-
jeffory broughton -
Jim Walls -
John Becker -
Peter Laws -
R.T.Liddy -
Zach Metzinger