Band Width
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Re: Band Width
Hi Harry
just follow up
I finally got back to it and I just had it thrown together on some vector board and it worked beautiful. It could even detect when I walked near it. I think if I build one properly in a good shielded box it would be even better. For the input I just used 150k ohm resistor in place of the tuning transformer.
I was just looking for something that could pick up any kind of carrier up to around 400Mhz
just follow up
I finally got back to it and I just had it thrown together on some vector board and it worked beautiful. It could even detect when I walked near it. I think if I build one properly in a good shielded box it would be even better. For the input I just used 150k ohm resistor in place of the tuning transformer.
I was just looking for something that could pick up any kind of carrier up to around 400Mhz
Jalex2- Posts : 119
Join date : 2012-12-06
Age : 82
Location : Long Beach , Washington, USA
Re: Band Width
Hi again, long time, no see, no hear, no read.
Yes, with the correct choice of semiconductors it should work well over 100MHz. BF199 or any half-decent transistor. But remember that the gain will fall with frequency, it is just a question of how much.
I presume you will use wide-band ferrite beads to make broadband transformer? Instead of the tuned circuit?
But please let me/us know how you get on. I would be very interested.
Sorry for the delay responding, but Maj-Lis came home this evening and I have been planning it for days :-)
BR Harry - SM0VPO
Yes, with the correct choice of semiconductors it should work well over 100MHz. BF199 or any half-decent transistor. But remember that the gain will fall with frequency, it is just a question of how much.
I presume you will use wide-band ferrite beads to make broadband transformer? Instead of the tuned circuit?
But please let me/us know how you get on. I would be very interested.
Sorry for the delay responding, but Maj-Lis came home this evening and I have been planning it for days :-)
BR Harry - SM0VPO
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Band Width
Hi Harry
I am looking for a wide band amp. Something like 400k to 100mhWould your IF amp below work if you remove the tuned input?
Cascode Novel IF strip for FM
Also Can you tell me a little about matching an antenna to an amp
Does a coil to ground on an input change the band
width if there is no cap across it?
A simple Jfet with the antenna connected to the gate seems perfect and works good but is there a way to improve on it?
I realize a wide band has less gain but I figure another stage will fix that.
How have you been these days
Thanks Jim
Jalex2- Posts : 119
Join date : 2012-12-06
Age : 82
Location : Long Beach , Washington, USA
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