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Components and Circuits For discussions about component types, alternatives and availability, circuit configurations and modifications etc. Discussions here should be of a general nature and not about specific sets. |
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16th Nov 2014, 2:37 pm | #1 |
Dekatron
Join Date: Apr 2011
Location: Cornwall, UK.
Posts: 13,454
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Regenerative receivers.
Has anyone tried this concept for consistent regen level:
http://www.kearman.com/vladn/hybrid_feedback.pdf I've also read that a similar effect can be got in the Armstrong topology by using a CR combination in the feedback network. If I can find the link for that I will post it. Lawrence. |
16th Nov 2014, 2:48 pm | #2 |
Dekatron
Join Date: Apr 2011
Location: Cornwall, UK.
Posts: 13,454
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Re: Regen's
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16th Nov 2014, 2:52 pm | #3 |
Dekatron
Join Date: Apr 2012
Location: Wiltshire, UK.
Posts: 14,007
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Re: Regen's
I've never thought of "Vackar-izing" a regenerative stage - though I've used Vackar (and related Seiler) circuits in VFOs.
They're probably the easiest way to get relatively-linear tuning and good frequency stability if you need only a small range of tunability (my application was as an 8MHz VFO that got multiplied to cover 144-146MHz). "AGC" in a regen stage is an interesting idea - it of course would only really work in situations where you're trying to receive a signal where there's a constant carrier. Given the relatively poor selectivity of regen stages when the regen's not turned-up very much I'd be concerned about the AGC being activated by strong off-frequency local signals. Still, it's an interesting thing to think about! [my personal interest is in phase-locked synchronous detectors] |
16th Nov 2014, 3:48 pm | #4 |
Dekatron
Join Date: Apr 2011
Location: Cornwall, UK.
Posts: 13,454
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Re: Regenerative receivers.
Here is the guy who wrote the article in the first link, it's a utube video in 2 parts, here is the 1st part, I will add another link for the 2nd part to this post if I can find it.
In this 1st part he shows the tuning range of the hybrid Vackar/Armstrong Regen and also the amplitude of the osc across that range when set to the sweet spot, the range is approx 3.3 Mhz to approx 9 Mhz so a tuning ratio of nearly 3x http://www.youtube.com/watch?v=Frg5RYz84gs EDIT: Here's the link for the 2nd part, same frequency coverage, he has set the Regen threshold for the sweet spot for AM reception as that is the best test. http://www.youtube.com/watch?v=zKRpV...ature=youtu.be Lawrence. Last edited by ms660; 16th Nov 2014 at 3:55 pm. Reason: Link and text addition |