Re: Elad FDM-DUO /// PTT Out failed?

Paul Andrews


What is the purpose of the 1-ohm resistor at the collector of Q14?

Q14 is the NPN transistor used for the PTT output.

73 - Paul - W2HRO

On Mon, Feb 3, 2020 at 9:41 AM Paul Andrews via Groups.Io <> wrote:

Thanks for confirmation.  I replaced Q14 and my PTT out is working again.

The BC817 cost only $0.06 but the replacement requires some planning.   The SOT-23 device is very small.  Good soldering tools and a magnifying glass is required with my 60 yr old eyes.

It's far better not to damage Q14.

I have another question:. Does the SW2 waterfall offer a speed between "fast" and "2 sec"?    For digital modes - 1 second and sync to clock would be very helpful.

73 - Paul - W2HRO

73 - Paul - W2HRO

On Mon, Feb 3, 2020, 06:32 Vianney Colombat <vianney@...> wrote:

Hello Paul,

Q14 is a BC817. Open a support ticket here if you need further assistance.


Il 01/02/2020 03:45, Paul Andrews ha scritto:
Hello.  Never work when you're tired.  :(

I accidentally applied 12vdc (no current limit) to my Elad DUO PTT Out port.

I believe I might have fried the NPN transistor.   An ohmmeter shows 10k ohms across the PTT but no path to ground is seen when the radio is keyed.

I opened the radio and found Q14 looks like the PTT NPN.   Can anyone verify this is the PTT NPN?

Has anyone replaced this Q14?    Any big risks.

I'd hate to send this back to Italy for repair.

73 - Paul - W2HRO


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Paul Andrews
SVP - Sales & Marketing
TelVue Corporation
1-800-885-8886 x102

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