Search found 36 matches
- Sun Dec 31, 2017 5:38 pm
- Forum: General Discussion
- Topic: Santa Claus Christmas Music Box repair
- Replies: 0
- Views: 79518
Santa Claus Christmas Music Box repair
Judging from online reviews a significant fraction of the polyresin-based Christmas-theme Music Boxes coming out of China have problems brand-new out of the box, right up to totally disfunctional. I thought it worthwhile to devote a little webpage on my website to the diagnosis and repair of a parti...
- Sat Dec 16, 2017 10:37 am
- Forum: General Discussion
- Topic: Experimental analog-circuit gas detector / alarm
- Replies: 2
- Views: 38823
Re: Experimental analog-circuit gas detector / alarm
NeilXu wrote : " Hi...i am a new user here. I took a look at your circuit and there a few things that I can mention. Firstly, if you need something as complex as a GSM Modem, you will need to create a LabVIEW instrument for it if that is possible. If you know the exact input you are going to re...
- Mon Oct 30, 2017 3:58 pm
- Forum: General Discussion
- Topic: Experimental analog-circuit gas detector / alarm
- Replies: 2
- Views: 38823
Experimental analog-circuit gas detector / alarm
For anyone interested I've put online on my website a description of my experiments resulting in the development of an experimental gas detector / alarm based on analog circuitry, and not involving any digital electronics : http://ki3u.byethost3.com/Instruments_etc/Exp_Gas_Detector/Exp_gas-detector-...
- Mon Jun 26, 2017 5:52 pm
- Forum: General Discussion
- Topic: Cooling troubling electronics
- Replies: 0
- Views: 79803
Cooling troubling electronics
Sometimes often enough you can get lucky and implement a quick and easy fix, if only a temporary one, of
a troubling electronic device :
http://ki3u.byethost3.com/Radio-Physics ... onics.html
Berj / KI3U
a troubling electronic device :
http://ki3u.byethost3.com/Radio-Physics ... onics.html
Berj / KI3U
- Tue May 02, 2017 9:34 am
- Forum: General Discussion
- Topic: Raising the frequency of a quartz crystal
- Replies: 2
- Views: 22678
Re: Raising the frequency of a quartz crystal
Hi Jeff r tnx. Well it's a useful skill to change these older crystals for modern use - there are still tons of them available. Lets note that the FT 243 types were intended for vacuum tube circuits, but as we see in the article the crystal oscillates nicely in a one-transistor test oscillator power...
- Sat Apr 29, 2017 3:48 pm
- Forum: General Discussion
- Topic: Raising the frequency of a quartz crystal
- Replies: 2
- Views: 22678
Raising the frequency of a quartz crystal
For those interested I have some data on raising the oscillation frequency of quartz crystals, in particular moving a
5675 KHz crystal up to 6109 KHz :
http://ki3u.byethost3.com/Radio-Physics ... uency.html
Berj / KI3U
5675 KHz crystal up to 6109 KHz :
http://ki3u.byethost3.com/Radio-Physics ... uency.html
Berj / KI3U
- Sat Aug 27, 2016 9:14 am
- Forum: General Discussion
- Topic: Very simple, very effective outboard CW Audio Filter
- Replies: 0
- Views: 73729
Very simple, very effective outboard CW Audio Filter
It is possible to realize an excellent CW radiotelegraph outboard passive audio filter with just one inductor and one capacitor. I describe this in some detail on this page of my website : http://ki3u.byethost3.com/Radio-PhysicsDIR/ecomDIR/Simple_passive_CW-filter/Simple%20passive%20CW%20audio%20fil...
- Tue May 03, 2016 3:44 am
- Forum: General Discussion
- Topic: Reversing the Midland 23-136 SWR Meter's ports
- Replies: 0
- Views: 40298
Reversing the Midland 23-136 SWR Meter's ports
If convenience in the radio station calls for it, it couldn't be simpler to reverse the port directions of the Midland 23-136 SWR and Power Meter (and similar units of this rebrand instrument) : http://ki3u.byethost3.com/Radio-PhysicsDIR/Radio_Equipment/Midland%2023-136%20SWR%20Meter/Reversing%20the...
- Wed Aug 19, 2015 7:32 pm
- Forum: General Discussion
- Topic: Amplified Computer Speakers converted to Intercom
- Replies: 0
- Views: 24444
Amplified Computer Speakers converted to Intercom
I've converted an old MLI 691 PA amplified computer speakers system to a wired intercom :
http://ki3u.byethost3.com/Radio-Physics ... ercom.html
The conversion is very simple and works really well.
Berj / KI3U
http://ki3u.byethost3.com/Radio-Physics ... ercom.html
The conversion is very simple and works really well.
Berj / KI3U
- Sun Nov 09, 2014 10:35 pm
- Forum: General Discussion
- Topic: Acoustic Coupler for Amateur Radio Digital Modes
- Replies: 0
- Views: 19798
Acoustic Coupler for Amateur Radio Digital Modes
For amateur radio digital modes I built an acoustic coupler interface between the transceiver and computer to eliminate computer problems on key down. It's worked well so far. A friend of mine suggested I describe it online, so I've just put it up on my website if anyone's interested: http://ki3u.by...