Spike on 100D when i key mic

[ve2xx]

I have not used my 100 D for a while, i have Thetis 2 10 3 7 protocol 1 and the FW on Angelia is 5,4

Is there a setting i have overlooked to prevent a spike when i key the mic or will going to the latest FW ( 5.9) resolve this.

Thanks

Stu
ve2xx

[w-u-2-o]

There are a lot of different kinds of "spikes". If you post a screen shot of what the spike looks like that would help.

Attaching images to your posts is easy. Start a reply, select the "Attachments" tab below the post editor window, and click "Add files". You can also place the image to appear inline in the post by choosing that option.

[ve2xx]

the video will show the burst at the end

So its actually when i release the ptt i see a spike, it has nothing to do with power level
Wavenode power meters are capable of detecting rather quicky any power change

[K1LSB]

What does an SWR meter in Thetis report?

Mark

[w-u-2-o]

The Wavenode is a fine instrument, so I'm inclined to trust it.

Since the Wavenode is showing it's a reverse power spike, the energy is not coming out of the 100D, and therefore there is no problem with the 100D, the firmware, or the software.

It would appear that your feedline and antenna may be strongly inductive and storing energy that is being released at the end of the transmission.

Would you describe your station, please? 100D, we know. Is there an external tuner? Amp? What are you using for feedline and antenna? Leave nothing out.

[ve2xx]

100d to 8877 amp abt 15ft ldf4 50 to input

Abt 220ft cable consisting of 170ft ldf6 50 1.25"
A 50ft jumper of 1/2" superflex to 2 el 40m beam

Tower is 125ft away 75ft tall

I removed tuner no difference. Swr on 40 is 1.3:1


I dont see this behaviour on my orion 2 board with identical software

Makes sense what you are saying abt inductive behaviour.
Strange though.

[w-u-2-o]

So this is a homebrew 8877 amplifier?

What kind of driver amp is being used with the Orion board?

[ve2xx]

Yes its hb on 40m
On 80 its a alpha77 it does the same thing i see that spike on ptt release


Re orion
I dont use the orion with tube amps.
I have ldmos amp for that radio
The driver is like 20w the max i need is 4-5w

[w-u-2-o]

Completely different setups.

Because this is a reverse power spike, it is extremely unlikely the problem is with the 100D.

You might try the Orion and LDMOS amp combo on the 40 and 80 antennas and see if the it exhibits the same behavior.

[ve2xx]

When i get back next wk ill put the wavenode right at 100d and put a dummy load see how it behaves

Thanks for all your replies / suggestions.

[K1LSB]

As a valid (and easy to obtain) data point, I repeat my simple question:

What does an SWR meter in Thetis report?

Mark

[ve2xx]

Mark sri i missed that first time
I will check and report back when i get back
73's

[ve2xx]

Mark
It actually reports close to the same .

I am going to update my FW on 100D and see if there is any change.

Thanks

[w-u-2-o]

With the energy coming from a source downstream of the power meter, why are you focusing on 100D firmware?

Before you do that, what happens if you put a dummy load in place of the antenna? I bet this problem goes away if you do that.