CRT 6900N

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Horris12
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CRT 6900N

Post by Horris12 »

So I have a CRT6900N and have been using it for a few weeks now with no problems. This week I put the antenna a 1/2 wave silver rod (using this while i set up my A99) up on a higher mast. Now my modulation on SSB is shockingly poor with poor comms reports. I have had reports of it over modulating or sounding tinny.

I will say that everything is the same as it was before mic, Radio settings, power supply. Nothing has changed on that end. My modulation with these setting before the antenna was put up higher was absolutely perfect.

Mic- Power mic
Power supply- 13.8v 10A
Fuse- 15A as specified

Now I am at the point where I have tried everything to sort it out on SSB to no avail so the radio my get binned I have had enough with it.

If anyone can help before the 6900 meets the bin it would be a great help.

Cheers
Horris!
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ch25
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Re: CRT 6900N

Post by ch25 »

Check on dummy load and come back with result.
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Mudslinger
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Re: CRT 6900N

Post by Mudslinger »

Does it sound ok on other modes? The Mic may have gone faulty, as they are not the best to start with.
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original45
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Re: CRT 6900N

Post by original45 »

A couple local lads I talk too use the 6900 n. What I noticed is they all use the kpo power mic and this sounds fantastic and very loud on fm but on ssb audio sounds poor as you say tinny also.
Another noted issue with them and the a!inco dx 10 is rf issues all the time.
Jumping channels, noise in audio transmit no 5 warning alarm .
This hasn't been just 1 but at least 5 I know of.

Myself even constant rf issues more so with a Antrim 99.

Most these issues have been resolved rf wise by ferrite chokes and ferrite clip on to power cables ,coax,Mic leads especially if power mics used.

Try reducing audio on ssb. This is common in ssb on alinco dx 10 on ssb with audio turned up however once chokes are fitted you can again turn up the audio full on ssb.
Strange radios and I'm no clever expert but having had the radio time ,having it looked at by a radio engineer we came to conclusions they seem to be riddled with rf .

Ground earth antenna mast. Ground earth your radio, psu ,any amp properly.
Good luck with it.nice radio for the money but from the experiences of my own and local lads are rarely without using chokes, ferrites earthing 100% usable without rf issues
Last edited by original45 on 31 Dec 2021, 23:40, edited 1 time in total.
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cb4ever104
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Re: CRT 6900N

Post by cb4ever104 »

original45 wrote: 31 Dec 2021, 15:04 A couple local lads I talk too use the 6900 n. What I noticed is they all use the kpo power mic and this sounds fantastic and very loud on fm but on send audio sounds poor as you say tinny also.
Another noted issue with them and the a!inco dx 10 is rf issues all the time.
Jumping channels, noise in audio transmit no 5 warning alarm .
This hasn't been just 1 but at least 5 I know of.

Myself even constant rf issues more so with a Antrim 99.

Most these issues have been resolved rf wise by ferrite chokes and ferrite clip on to power cables ,coax,Mic leads especially if power mics used.

Try reducing audio on ssb. This is common in ssb on alinco dx 10 on ssb with audio turned up however once chokes are fitted you can again turn up the audio full on ssb.
Strange radios and I'm no clever expert but having had the radio time ,having it looked at by a radio engineer we came to conclusions they seem to be riddled with rf .

Ground earth antenna mast. Ground earth your radio, psu ,any amp properly.
Good luck with it.nice radio for the money but from the experiences of my own and local lads are rarely without using chokes, ferrites earthing 100% usable without rf issues
I miss the simpler days when you could just go out and buy a rig , DV27 , stick it on a biscuit tin and away you went :)
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original45
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Re: CRT 6900N

Post by original45 »

We said exactly that .It was so so simple but we're learning again .
Happy New year all
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