Hi just a quick question. Is anyone using a preamp on the CRT 9900?

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Radiobum99
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Hi just a quick question. Is anyone using a preamp on the CRT 9900?

Post by Radiobum99 »

I’m thinking of getting a preamp to keep my CRT9900 cool. Any advice on which preamp is best for this?
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Re: Hi just a quick question. Is anyone using a preamp on the CRT 9900?

Post by Alan Pilot »

If you don't have enough qrm you will with one of them.
To be honest they are not worth it well i don't think so as they just boost the hiss in the background.
Others may have a different view.
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ch25
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Re: Hi just a quick question. Is anyone using a preamp on the CRT 9900?

Post by ch25 »

No need for preamp on 27MHz. It only worsen S/N ratio.
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Re: Hi just a quick question. Is anyone using a preamp on the CRT 9900?

Post by Werthers »

The CRT9900 is ok not the best radio to go for mind... To keep it cool during transmit periods. Make sure your SWR is OK it always helps to check with a good SWR meter, make sure your antenna is good and check your coax.

When radios get to hot its always something to do with the antenna although some transceivers get hot regardless but it always helps to make sure your not torturing your transceiver first. The CRT9900 has a high output power. No need for a preamp. The receivers work just fine.

Noise floor can be a problem.
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Re: Hi just a quick question. Is anyone using a preamp on the CRT 9900?

Post by Radiobum99 »

Thanks for the replies. I’m using a 10 meter single band dipole and have a SWR of around 1.3.

The reason for thinking about a preamp is to take some heat out of the 9900. By being able to lower it’s output from 50 to 4 watts and letting an amp take up the slack I figure it should cool the radio down a lot.

Then again I don’t want sit there having my eardrums tormented with even more hiss than I already got :D
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Re: Hi just a quick question. Is anyone using a preamp on the CRT 9900?

Post by Andy »

Ah, do you mean a power amp, not a pre-amp?
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Re: Hi just a quick question. Is anyone using a preamp on the CRT 9900?

Post by Radiobum99 »

Andy wrote: 06 Aug 2021, 12:38 Ah, do you mean a power amp, not a pre-amp?
Sorry yes, I’m new to the ham radio hobby aside from a bit of CB’ing in the distant past.

A power amp yes. I’ve found one with a pre-amp feature and thought if I’m going to buy one I may as well have this feature.

The amp I want is 300 watts but my antenna is rated a 1000 so hopefully nothing should explode.
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Re: Hi just a quick question. Is anyone using a preamp on the CRT 9900?

Post by ch25 »

What antenna do you have and how high over the roof /ground?
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Re: Hi just a quick question. Is anyone using a preamp on the CRT 9900?

Post by Radiobum99 »

I have a 10 meter single band folded dipole antenna, 18 foot long, 1000 watt max rating strung to the wall outside about 18 foot above ground level. I've not had it long and I'm not sure if its any good or not.
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ch25
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Re: Hi just a quick question. Is anyone using a preamp on the CRT 9900?

Post by ch25 »

Are you using this antenna for local contacts or dx and why it's folded since it's short wire after all.
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Re: Hi just a quick question. Is anyone using a preamp on the CRT 9900?

Post by Radiobum99 »

ch25 wrote: 06 Aug 2021, 17:05 Are you using this antenna for local contacts or dx and why it's folded since it's short wire after all.


Just locals atm. I'm very new to this game and get a lot of things mixd up'

Here it is :

Image

This Listing is for a 10m half wave Dipole, the overall length is approximately 5 meters.The antenna is constructed with Poly Weave Nylon coated multi strand antenna wire The Dipole centre is encapsulated and capable of handling 1000 watts of power. Also the Poly Weave is fitted with Nylon dog bones so the use can simply add their coax and plug and away you go.
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ch25
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Re: Hi just a quick question. Is anyone using a preamp on the CRT 9900?

Post by ch25 »

Local use vertical polarisation. You, horizontal. It is 25dB attenuation give or take. So you hear s**t. 25dB is 4s units less.
Hang it vertical.
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