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Can you tell me the approximate frequency coverage of the completed receiver? Thanks!
Asked by Anonymous on August 20th, 2016.
This radio kit will cover the AM radio band along with the SW radio band.
Difficult to tell. I built the kit but there's no way to determine the frequency you are on. I just know that one setting is for the AM band, and the others are for shortwave. I'm sure it covers at least the 5-10mhz portion of the SW bands.
Does it cover the 80 Meter [3.5-4 MHz] and 40 [7.0-7.3 MHz] Meter Ham Bands??
A good way to calibrate this radio would be to find the frequency-time broadcast station WWV - WWVA in Ft. Collins CO, and Hawaii on the lower bands of 2.5, 5, 10 MHz at night, and 15, 20 MHz daytime. It will give you the frequencies to calibrate your radio, plus time of day in Zulu time, plus weather info for mariners and "other related information" according to the announcer at the top and bottom of the hour. WWV announcer id a male voice while WWVA is a female voice There is also CHU in Canada, but I do not have their frequencies at hand. 73's de W4FJF.
I have a crazy question. I was reading about cold cathode operation. What if instead of a 45v or high voltage source what if I used a quartz ocilator to make a frequency high enough to energize the tube and run it off say 3 volts in a radio circuit instead?
Asked by Anonymous on February 21st, 2016.
The tube would light up in a
A flash & that would be the
The end of the tube :(:(
I am struggling to identify capacitor
Beside the 3 ceramic with have a clear 503 label so 0.05 microF
The other four are all blue 'ceramic' with no label
Asked by Anonymous on August 16th, 2020.
These capacitors also have a code printed but it can be difficult to read. A magnifying glass and good lighting can be really helpful. If you have a multimeter that can accurately read capacitance, you can use the meter to identify the caps as well.
My receiver picked up a lot of AC line hum from the antenna. I solved this by winding 15 turns of wire on a form thinner than the radio's coil, the sliding the thin coil inside the main. The inductive pickup, eliminated the AC line hum. Also used a pair of micro-switches to change bands. In lieu of the HI-Z headphones, you can put together a simple LM386 audio amp and use an 8-ohm speaker, as I did. Uses more current, but I fashioned a power supply out of 45VDC and a 5VAC wall warts. You'll need to filter the 45VDC wart better, and regulate the 5VAC wart to provide 1.5VAC for the tube filaments. The 1.5 can be achieved with a correct value resistor (or variable resistor), but I built a simple regulator using a LM2596. Both chips datasheets show how to do this.
Asked by Anonymous on January 24th, 2017.