[ARC5] More BC-230 on 30 Meters

[Brian Clarke]

Hello Dave,

The gimmick capacitor was the right concept. As you surmise, and I tend to 
agree with you, you were getting too much oscillator power. This means that 
you were achieving too much positive feedback - which is great for getting 
an oscillator started - but it can lead to squegging and temperature-related 
drift.

The trick in oscillator design is to have just enough positive feedback 
overall to overcome circuit losses, so that the output level remains stable, 
with perhaps a little in reserve to ensure reliable starting. So, experiment 
with your feedback.

73 de Brian, VK2GCE.

On Monday, August 04, 2014 10:27 PM, you said:


> <snip>
>
> Crystal needs to be active.  A less-active crystal- one of the 
> "mini-holder" type- is "whoopy" and
> the active crystal has a little "sing-song" as well. I tried installing a 
> "gimmick" cap between the OSC tube's plate and grid and this did almost 
> eliminate the chirp, but it had the unforseen result of making the rig 
> drift lower
> on key-down when using "stock" MOPA configuration.
> Probably because it's drawing too much current and heating-up, so I 
> removed the gimmick.
>
> <snip>
>
> 73 DE Dave AB5S