Hi Tim, Yes a clamping diode will slow down the release time of a dc
relay. The time constant (release time) is approximately L/R, where L
is the relay coil inductance and R is the coil resistance. If the
release time is objectionable, it can be shortened by adding a zener
diode (typically with a zener voltage roughly equal to the power
supply voltage in series with the clamping diode.
73,
Jim W8ZR
Sent from my iPhone
> On Dec 11, 2022, at 7:00 PM, Tim Duffy <k3lr@k3lr.com> wrote:
>
> Hello Jim
>
> Does that clamping diode across the coil affect the TX key up delay time? As
> in "slow it down"?
>
> 73
> Tim K3LR
>
> -----Original Message-----
> From: Amps [mailto:amps-bounces@contesting.com] On Behalf Of MU 4CX250B
> Sent: Sunday, December 11, 2022 5:49 PM
> To: Steve London
> Cc: amps@contesting.com
> Subject: Re: [Amps] Noisy relay
>
> Steve, you might be hearing the induced voltage kick caused by the
> inductance of the coil. Try putting a clamping diode. A small signal
> diode like a 1n914 will work fine,
> 73,
> Jim w8zr
>
>
> Sent from my iPhone
>
>> On Dec 11, 2022, at 9:39 AM, Steve London <n2icarrl@gmail.com> wrote:
>>
>> Commander HF-2500..
>>
>> Every time the T/R relay goes back to receive, I'm getting a pretty big RF
>> spike that I can hear in the receiver. This has nothing to do with the
>> transceiver hot switching or RF stored in the tank circuit. I can reproduce
>> it just by cycling the T/R relay in the amp with a separate cable, not
>> connected to the transceiver, and not transmitting.
>>
>> Suggestions ?
>>
>> 73,
>> Steve, N2IC
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