Help?!

Everything technical about radio can be discussed here, whether it's transmitting or receiving. Guides, charts, diagrams, etc. are all welcome.
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piratefm
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Help?!

Post by piratefm » Tue Dec 19, 2017 8:45 pm

I’m a bit wet behind the ears with stuff like this. What does this mean? I’m confused as to why there are two FWD. totally confused as to set the whole thing up!
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geegosh
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Re: Help?!

Post by geegosh » Tue Dec 19, 2017 9:20 pm

I believe this is different measurements to test for as a quick diagnostics tool on the transmitter. In other words, each of those choices on that rotary measures for that value it's stating. I'm presuming there is a voltage or measurement meter of some sort on the front with a needle..? FWD Power 2.5W is probably from a driver, FWD Power 25W is measuring at final output stage post PA.

So for example, when set to FWD Power 2.5W, the meter needle on the front should jump to show FWD Power 2.5W is correct.

This does not have any impact on actually using/operating the transmitter, although you would want to measure your reverse power and deviation once on-air.

I'm fairly sure this is what it is, however my answer is based on my experiences with a lot of SBS kit that has a similar style thing on the front of their transmitters, power amplifiers etc.

piratefm
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Re: Help?!

Post by piratefm » Tue Dec 19, 2017 10:51 pm

geegosh wrote:
Tue Dec 19, 2017 9:20 pm
I believe this is different measurements to test for as a quick diagnostics tool on the transmitter. In other words, each of those choices on that rotary measures for that value it's stating. I'm presuming there is a voltage or measurement meter of some sort on the front with a needle..? FWD Power 2.5W is probably from a driver, FWD Power 25W is measuring at final output stage post PA.

So for example, when set to FWD Power 2.5W, the meter needle on the front should jump to show FWD Power 2.5W is correct.

This does not have any impact on actually using/operating the transmitter, although you would want to measure your reverse power and deviation once on-air.

I'm fairly sure this is what it is, however my answer is based on my experiences with a lot of SBS kit that has a similar style thing on the front of their transmitters, power amplifiers etc.

You’re right mare, it’s does have a meter to show those selections. That makes sense about the two FWD options. So, with the REV PWR it has 2.5 w next to it. Does that mean that if the transmitter is set up correct, it should show a max of 2.5 W on the meter when selected “Rev Pwr”?.....I’m guesssing that’s some safe level?.

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Analyser
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Re: Help?!

Post by Analyser » Tue Dec 19, 2017 11:08 pm

The reverse power selection on your rig is to see how many watts are being reflected by your aerial back to the transmitter. With a perfect aerial very little power will be reflected, and with a bad aerial a lot will be reflected. This is just a setting on the meter to show you how much (up to a maximum of 2.5 watts).

The radio of the forward power going out to the reflected power coming back from the antenna is also called the SWR or standing wave ratio. Although you can't read SWR directly from that meter you can work it out from places like this...

http://ac6v.com/swrmeter.html

As an example, for 2.5 watts reflected back to your transmitter which is giving out 25 watts, the SWR would be about 2:1. To put this in perspective, transmitters commonly have protection to shut themselves down at 3:1.

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Re: Help?!

Post by Analyser » Tue Dec 19, 2017 11:09 pm

Also, a picture of the whole transmitter would be nice. It looks tidy but a bit home-made (not necessarily a bad thing).

piratefm
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Re: Help?!

Post by piratefm » Wed Dec 20, 2017 9:57 pm

Here are some pics of my set up in my bedroom.
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Maximus
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Re: Help?!

Post by Maximus » Fri Dec 22, 2017 11:07 pm

You’ll definitely be sounding good on air with that lot! I’m personally a big fan of Omnia.


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