10Ghz Demi question....
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Tony Gallagher <tony_g_ireland@...>
This weekend we were setting up the other two 10Ghz kits and getting them ready for air.
However we encountered a very odd problem. The units are Demi 10Ghz units to be used with FT290s using the DC voltage from the rig over the IF to key it. The transverter will work and TX correctly when used with my FT817 which is modded to send 5VDC over the IF on TX, but it wont work with the FT290s!!! The 5VDC on the IF is present from the FT290 radio when the radio transmits but when its connected to the Demi, the IF voltage drops from 5VDC to 1.2Volts, I assume this drop is causing the Demi to not switch to TX mode. Why is this happening? Thanks in advance everyone. Tony EI4GHB
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Tony Gallagher <tony_g_ireland@...>
Sorry, I should have mentioned, we tried two different FT290s, MK1 and a MK2 and also with two brand new transverters!!!! Makes things even more confusing! :)
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Tony
--- In ukmicrowaves@..., "Tony Gallagher" <tony_g_ireland@...> wrote:
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Andy Talbot <andy.g4jnt@...>
Output resistance of the FT290 DC feed (what's the betting someone arbitrarily decided on a 10k R because its a nice value) vs. input resistance of the Demi ....................?
Andy G4JNT wobbleU cubed .g4jnt.kom 2009/6/7 Tony Gallagher <tony_g_ireland@...>
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Geoff Blake <geoff@...>
On Sun, 7 Jun 2009, Tony Gallagher wrote:
Sorry, I should have mentioned, we tried two different FT290s, MK1 and aTo the best of my knowledge, the FT290RII does not have the +ve feed on TX as standard - mine didn't. Sam G4DDK has the mod to add the +ve feed on his web site. That aside, it seems that the series resistor is to high, if it is dropping the voltage to 1.2V. I used 8K2 to switch a DB6NT transverter successfully. Geoff -- Geoff Blake G8GNZ located near Chelmsford, Essex, U.K. Please reply to: geoff(at)palaemon(dot)demon(dot)co(dot)uk Using Linux on Intel & Linux or NetBSD on Sun Sparc platforms Please avoid sending me Word or PowerPoint attachments. See <http://www.gnu.org/philosophy/no-word-attachments.html> ----------------------------------------------------------------- This E-mail and any attachment(s) are strictly confidential and is intended solely for the addressee(s). If you are not the intended recipient please notify <postmaster(at)palaemon.demon.co.uk> and the sender by return and permanently delete the message. You may not disclose, forward or copy this E-mail or any of its attachments to any third party without the prior consent of the sender. ----------------------------------------------------------------
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