Posting Comment for "A Working Receiver"

*Author Name
Email Address
Website URL

About Posting a Comment

Comments are moderated before they will appear on the website, this is a manual process and may take some time. Please be patient.

Author Name is a required field.

Email Address is optional, but without one I won't be able to contact you back. It is never shown or linked on the website. You can always just email me if you'd rather not post a public comment. I generally reply in-line with a comment rather than email you back, unless I want to discuss something in private or off topic. Please check back to see when I reply.

Website URL is optional, if supplied the Author Name will be hyperlinked to this URL.

You may use wikitext in the body, preview may be handy here. Don't worry if you can't figure them out, just give me a hint what you want linked to what and I'll do it during moderation. Wikitext is not BBcode!

Spammers: Please don't bother wasting your time scripting up posts to this form. Everything is moderated, your post will never be seen on the web even transiently, there is no way to even view it by its internal ID, it will never be indexed. I will simply delete your post in the moderation interface. If I'm your target audience you're really on the wrong track; I'll never click on a URL in your garbage. The post content is not emailed to me (and I don't use a Win32 mail client anyway), I view the posts in plain text in the moderation interface so no clever tricks of any kind will make anything you type be interpreted by anything other than me, a human. Just give up and go elsewhere please!


6th January 2009 06:00

Alan Yates wrote...

Anthony,

The usual rule with broadband RF transformers is at least 3-5 times more than the load impedance at the lowest frequency of interest. In this case for a 50 Ohm system more than 250 Ohms (10.6 uH at 3.68 MHz), so 400 (or 17.3 uH) would be fine.

For the FT23-43's I was using that is at least 8-9 turns. My transformers did not have that many turns, but still worked fairly well. (They had 7 turns which is ~7.8 uH or 180 Ohms which scrapes though in the 3-5 times rule of thumb.)

Regards,

Alan

5th January 2009 14:56

Anthony Sotillet wrote...

Hi Alan. I'm writting you from Venezuela. Let me ask you a little thing. What should be the reactance of a DBM transformer? 400 ohm? or 200 ohm?