Winston, Glad to have you with us. Do not be intimidated. There are those of us who talk and do nothing. Can't think of any names right now but . . . We all...
5710
Paul W. Ross
deadgoose38
Dec 1, 2007 2:13 pm
I wonder if you could hook a microprocessor up to program the tracking? In a superhet, you track on the band ends and the geometric mean in the middle of the...
5711
larry allen
laryacan
Dec 1, 2007 6:23 pm
Hi Paul... You bring back many memories for me.... I developed a strong interest in radios back in the mid 50's... around age 10... Santa claus got me a tube...
5712
Larry Beaty
beatysmills
Dec 1, 2007 6:31 pm
Paul, that is exactly what I am proposing. You can do it also with a Static RAM. Each memory location is a distance in the band. Like every 5 KHz. Then...
5713
g4dfv
Dec 1, 2007 6:33 pm
Taking a sledgehammer to crack a nut springs to mind! Duncan G4DFV [Non-text portions of this message have been removed]...
5714
Larry Beaty
beatysmills
Dec 1, 2007 6:57 pm
Duncan, Very true - the uP is such a powerful tool. However it does simple tasks equally well. Like long time delays. As to a TRF, the present tuning of...
5715
Winston Smith
winstonsmith_99
Dec 2, 2007 2:00 am
Thanks, Bill. ZOW! Your Homebrew page is truly stunning! It's a real feast for the eyes and very inspiring. Today I exhumed my old Heathkit RF Signal...
5716
Winston Smith
winstonsmith_99
Dec 2, 2007 2:08 am
Larry, That boy of mine, he's my best friend. He's great help in my old-tyme woodshop, and can he ever joint a board using only a block plane. That's talent....
5717
kyoritsu
Dec 2, 2007 1:20 pm
Is there a way to use these things with tube regens? I've tried them for both DC for the filaments and low voltage B+, but they make too much noise. I've got...
5718
Des
d29602960
Dec 2, 2007 2:23 pm
Hi Rob and the group, I have used those wall-warts in the past for various radio projects (including regens and DC receivers) and like you I found some of them...
5719
Larry Beaty
beatysmills
Dec 2, 2007 7:45 pm
Winston, Now you are right down my alley. I am a power supply engineer. I have gone all the way to a battery powered 5KW power supply for traffic signals. I...
5720
wd4nka
Dec 2, 2007 9:31 pm
Welcome to the group, ws. Don't worry about your ability to contribute, in fact one catagory that doesn't get a whole lot of banter [which i would like to see...
5721
Bill Cromwell
ku8h
Dec 2, 2007 10:14 pm
... Hi Rob, My approach would be similar to what Des described in his reply. I am perfectly willing to sacrifice the plastic case and add a line cord along...
5722
mpingo91
Dec 2, 2007 10:24 pm
Hi all, who'll help me to recognize BF961 dual-gate MOSFET leads? It's described in a datasheet of course and look like this: ...
5723
Kevin Purcell
kevin_g_purcell
Dec 3, 2007 12:04 am
Three methods Get the datasheet e.g. <http://www.chinaicmart.com/pdf/pdf_down.asp?id=169628> 0. By the tooth: The package drawing on the datasheet does have...
5724
Larry Beaty
beatysmills
Dec 3, 2007 3:35 am
Greg, Look carefully at the top to bottom of the plastic halves put together. From the drawing, I see the top half is thicker than the bottom half, and the...
5725
kyoritsu
Dec 3, 2007 9:27 am
Thanks, Des and Bill I'll open one up and see what I can do. I had been thinking of trying RFC chokes but wondered about the current requirements. How did...
5726
mpingo91
Dec 3, 2007 9:34 am
... As I wrote reality differs from designers ideas - all teeth of my transistor look the same (probably they make these leads with "out of shape", old...
5727
kyoritsu
Dec 3, 2007 9:49 am
Hi Winston, I've got all those books. They're all interesting. I especially like Secrets of Homebuilt... Old ARRL handbooks (up to the 1940s???) also have...
5728
mpingo91
Dec 3, 2007 9:50 am
One more question just for curiosity: how sensitive to damage are such MOSFETs as BF961? I don't mean about electrostatic charges etc. - could I damage it if I...
5729
Larry Beaty
beatysmills
Dec 3, 2007 2:33 pm
Greg, Keeping the electrostatic conditions under control, as long as your power supply can be current limited to say 20 mA and voltage down to within the range...
5730
Mike
mikrowaveman
Dec 3, 2007 7:21 pm
Rob, Here is an idea. Take a 12V and two 24V wall warts and series all of the outputs. This will give you a flexible set of output voltages 12V, 36V and 60V...
5731
Nick
pettefar
Dec 3, 2007 9:26 pm
Hi, does anyone have a circuit using one or two ecc86 valves? I have bought a lovely but small-ish wooden (coffee) box in a charity shop and would love to...
5732
Kevin Purcell
kevin_g_purcell
Dec 3, 2007 9:28 pm
These devices are protected against static discharge (see the zeners in the datasheet). As for regular low Z so long as they are current limited you won't be ...
5733
Kevin Purcell
kevin_g_purcell
Dec 3, 2007 9:40 pm
If any of these wall warts are transformers-based then with the addition of a voltage doublers or quadruplers (some Si diodes and capacitors) you can get...
5734
Hue Miller
xtemporize
Dec 3, 2007 9:57 pm
I have seen these up to at least 36 volts and maybe up to 40 volts output. The higher voltage ones are decent material for tube type receivers. They do work as...
5735
Dimitri Aguero
d_aguero
Dec 3, 2007 10:27 pm
... I opened one. It is a transformer with a secondary terminated on a diodes bridge (made of 1N4004 silicon diodes) and an electrolytic capacitor, all...
5736
deadgoose38
Dec 3, 2007 10:28 pm
A quick Google check suggests that the tube is one of the "space charge" tubes. I'd think one of those circuits would be a good place to start. One section for...
5737
Kevin Purcell
kevin_g_purcell
Dec 3, 2007 11:59 pm
... But we're using them for tube regens! One of the least serious uses :-) I was assuming that these are pretty cheap and nasty. With a voltage doubler or...
5738
airshoo2
Dec 4, 2007 12:53 pm
400 Tubes for sale--reduced to $125+ shipping I have 400 tubes for sale, there are 120 minitures in org boxes and mostly all NOS, there are 80 8 pin octals in...
