atferrari

I want to implement a receiver to get only the time signal from WWW (10 MHz). Proof of a concept is the goal.

Since it is not the main point in my project I am looking for a "sure fire" circuit not needing more than the usual debugging.

I run across one here: http://www.qrp.pops.net/wwv_receiver.asp

My questions:

A) Dual MOSFET 40673 transistors are discontinued ones, not obtainable locally and hard to get (time and $$$$$$$$). Is it any modern one which I could use to replace them in the front end section?.

B) Regarding the ferrite toroids I have in my junkbox: how could I know if any one match the reccomended ones?

C) Is there any reason to use such an elaborate audio amplifier circuit or could it be replaced by something based on a audio amp IC?

D) Can anyone suggest another circuit, similar or SIMPLER, which I could build but "sure fire" granted?

Please do not propose alternatives other than RF receivers. Proof of the concept in play requires it!

(Yes I know that GPS exists. I really know that!) My RF practice is lost in time and have not time nor interest in experimenting. At least not this time.

Thanks for any help. I will certainly appreciate that.

__________________
Agustín Tomás
In theory, there is no difference between theory and practice. In practice, however, there is.

RadioRon

I think that this example circuit that you propose is too complicated for the basic job it must do, and if you want it bulletproof you should avoid a TRF receiver of this type. The most reliable and sure-fire receiver architecture is the super-heterodyne. That is why it is the most popular configuration.

You might want to consider using a single chip AM receiver suited to 10MHz operation. I googled and found one or two examples that include application circuits:
http://www.shfmicro.com/TEA5551T.pdf
or
http://www.nxp.com/acrobat_download/...072A_CNV_2.pdf
(althought the TDA1072 doesn't mention an input frequency range to 10MHz so not sure it is good).

__________________
RadioRon

on1aag

Hi Agustín,

First question: See what you can find, if it has two gates it will do.
BF961's and BF981's will probably work even better
than the 40673's.

Second question: None of the toroids in your junkbox are suitable, that's
why it's called the junkbox.
The T-cores are metal powdered cores, the FT-cores
are ferrite cores.

http://www.amidon-inductive.com/aai_specifications.htm

Third question: You don't actually need the audio amplifier, get the
circuit working and decide later if you want to add one.

This is what a T50-2 looks like.

on1aag.

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mneary

Are you expecting a good signal most of the time? You're a long way from Colorado Springs....