Hi all! see here: http://krysatec.benghi.org/phprs/images/201205010910_cvregen1.jpg http://krysatec.benghi.org/phprs/images/201205010910_cv.jpg You can try...
14706
dayleedwards88
May 1, 2012 9:33 am
Here is the file: regenfb.jpg link: ...
14707
dayleedwards88
May 1, 2012 9:57 am
A simple HT supply for valved sets is here: file name: htsupply.jpg Link: ...
14708
dayleedwards88
May 1, 2012 10:23 am
Thank you for the kind words! The diode does conduct assymetrically, as it is loosely forward biased into the "knee" region. As the Cathode becomes more...
14709
Naqoyqatsi (aka the I...
koyaanisqatsiuk
May 1, 2012 11:30 am
Unfortunately the link comes up as document not found....
14710
thb201
May 1, 2012 5:48 pm
The file is in the the Regenrx2 group in the files section. File name is htsupply.jpg John...
14711
thb201
May 1, 2012 6:00 pm
One suggestion. It might be a good idea in these type of circuits to put a 0.1uF cap from the base to ground for each transistor. Or a 1N4007 diode (anode to...
14712
Cecil Bayona
k5nwa
May 1, 2012 7:11 pm
I see what you are doing, it's a good idea, you are using the 1N4007 as a pin diode to control the feedback. The only possible issue is if you make the...
14713
Theosleaper
k1wyh
May 1, 2012 7:17 pm
Keep in mind that diodes are temperature sensitive and this may impact stability. This point has been brought up in the past, so will be on some emails at the ...
14714
thb201
May 1, 2012 8:15 pm
Would there be any advantage, or disadvantage, to using the higher speed equivalents to the 1N4007 such as the SF4007 or UF4007? John...
14715
Cecil Bayona
k5nwa
May 1, 2012 9:46 pm
Pin diodes are slow devices, they have a long carrier time, a faster device would not work as a PIN diode, which basically acts as a current controlled...
14716
Tom Lee
thomaslee59
May 1, 2012 10:31 pm
Exactly right; faster is definitely not better here. The suitably slow 1N4007 (and actually many, if not most, 1N4006) diodes are "accidental" PIN diodes; the ...
14717
dayleedwards88
May 1, 2012 11:14 pm
Here is a very simple aid for easily tracking multiple tuned stages in preselector and superhet receivers using air cored home wound coils. It is vital that...
14718
dayleedwards88
May 2, 2012 12:19 am
Any temperature change will usually, if not always affect the radio as a whole, ie freq drift. Any diode/feedback drift using this method I have found is...
14719
dayleedwards88
May 2, 2012 4:43 am
I have taken the liberty of sharing my latest regen set... actually a superhet design using a regenerative IF/detector. To be honest, I am blown away by the...
14721
dawmast@...
drm1173
May 2, 2012 8:18 am
Re: Reliable method for smooth regeneration control Regeneration is used in the Voltage Controlled Filter section of an analogue synthesizer like the MiniMoog....
14722
kyoritsu
May 2, 2012 8:29 am
I recently bought a Hallicrafters SX140. Ham band receiver, regenerative IF stage. It was a receiver I wanted a long time ago. Nearly 50 years ago, actually....
14723
dayleedwards88
May 2, 2012 8:31 am
Not really required. Any added C across the B E junction will slow the transition and further reduce efficiency.... these transistors are very slow to begin...
14724
dayleedwards88
May 2, 2012 9:40 am
Rob, Excellent observation!!! Yes, these are the problems with regen IF stages in a nutshell, and very well described!! The conundrum is simply the regen IF...
14726
dawmast@...
drm1173
May 2, 2012 4:31 pm
I have built a solid state version of a Jones Supergainer with an IF of 450 kHz. I use a FET vesion of a regenerative Medium Wave receiver as the regenerative...
14727
vladn123
May 2, 2012 10:15 pm
Regen detector is very prone to overloading by CW/SSB, even in a plain regen with a half-decent antenna. There are two solutions: 1. Increase the oscillation...
14728
dayleedwards88
May 3, 2012 12:18 am
Very good info and very interesting, THANKS!!. Thing is, none of this is really applicable to the sx140. The regen IF amp is at a fixed frequency of 1650Kc, so...
14729
vladn123
May 3, 2012 1:03 am
I did not imply that the subject of that paper is relevant to the this thread, I just referenced the example of a regen with an AF derived AGC, sorry if that...
14730
davidpnewkirk
May 3, 2012 1:42 am
... There is another approach (in addition to being able to adjust the RF input to the detector): Use an optimized, _high-capacitance-tuned-circuit_ detector....
14731
kyoritsu
May 3, 2012 1:58 am
Thanks for the suggestions. The challenge is to sandbag the front end performance for 80 and 40 meters on one hand (where the RF amp is more of a hindrance)...
14732
kyoritsu
May 3, 2012 2:24 am
Vladn, regarding increasing the oscillation amplitude, how would I do this? Make the regenerative IF amplifier more of an oscillator, less of an amplifier? For...
14733
vladn123
May 3, 2012 4:58 am
I downloaded the circuit diagram for sx140. I am actually puzzled by the regeneration adjustment method. 0.6v range on g3 is not enough for meaningful gain...
14734
dayleedwards88
May 3, 2012 8:33 am
vladn... Yep, Cgp... the screen lifted to RF. The AGC is a bit naughty too on this stage.... would work fine under threshold....
14735
davidpnewkirk
May 3, 2012 12:04 pm
... The 1961 review of the SX-140 in _QST_ describes the mechanism as CR1 acting as a variable ac ground for the suppressor grid dependent on the bias current...
14736
Carlo Strozzi
iz4kbs
May 3, 2012 1:14 pm
... Hi, I'm not able to locate any of your files in Yahoo's Regenrx group, can you please provide the exact link to the relevan folder ? The link that you...
