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Oh no, I've just ordered 2x 2SC2999 to do a comparison on :laugh:

Seriously though I don't expect to find a significant difference. The common base amplifier used in the 148GTL-DX has fairly predictable performance at 27MHz and the gain is fairly well defined by the components around the transistor.

The noise figure is going to be dominated by the common base topology as well and will be most affected by the setting of the transformer at the input.

I did do a quick youtube video about the 148 receiver sensitivity and how to ge the best alignment from an unmodified radio.

I'm afraid I have a poor voice for presentations and I do tend to waffle a bit but you may find this two part video to be of interest.

Cobra 148GTL-DX Receiver Alignment and Sensitivity Part 1 (of 2) - YouTube

I do plan to do another one with some minor mods on but I can't say when I will be able to do it

<blockquote data-quote="G0HZU" data-source="post: 328586" data-attributes="member: 19109">Oh no, I&#039;ve just ordered 2x 2SC2999 to do a comparison on :laugh:Seriously though I don&#039;t expect to find a significant difference. The common base amplifier used in the 148GTL-DX has fairly predictable performance at 27MHz and the gain is fairly well defined by the components around the transistor.The noise figure is going to be dominated by the common base topology as well and will be most affected by the setting of the transformer at the input.I did do a quick youtube video about the 148 receiver sensitivity and how to ge the best alignment from an unmodified radio.I&#039;m afraid I have a poor voice for presentations and I do tend to waffle a bit but you may find this two part video to be of interest.<a href="http://www.youtube.com/watch?v=2pRbw3MuYhs&amp;feature=related" target="_blank">Cobra 148GTL-DX Receiver Alignment and Sensitivity Part 1 (of 2) - YouTube</a>I do plan to do another one with some minor mods on but I can&#039;t say when I will be able to do it <img src="https://cdn.jsdelivr.net/joypixels/assets/8.0/png/unicode/64/1f642.png" class="smilie smilie--emoji" loading="lazy" width="64" height="64" alt=":)" title="Smile&nbsp; &nbsp; :)"&nbsp; data-smilie="1"data-shortname=":)" /></blockquote>

[QUOTE="G0HZU, post: 328586, member: 19109"] Oh no, I've just ordered 2x 2SC2999 to do a comparison on :laugh: Seriously though I don't expect to find a significant difference. The common base amplifier used in the 148GTL-DX has fairly predictable performance at 27MHz and the gain is fairly well defined by the components around the transistor. The noise figure is going to be dominated by the common base topology as well and will be most affected by the setting of the transformer at the input. I did do a quick youtube video about the 148 receiver sensitivity and how to ge the best alignment from an unmodified radio. I'm afraid I have a poor voice for presentations and I do tend to waffle a bit but you may find this two part video to be of interest. [url=http://www.youtube.com/watch?v=2pRbw3MuYhs&feature=related]Cobra 148GTL-DX Receiver Alignment and Sensitivity Part 1 (of 2) - YouTube[/url] I do plan to do another one with some minor mods on but I can't say when I will be able to do it :) [/QUOTE]

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