Small apartment crystal radio tips 💎
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- Опубліковано 24 січ 2025
- Experience the magic of crystal radio, while living in a confined apartment space, running 10 feet of antenna wire, in conjunction with conductor coil with taps, and 1N43A germanium diode.
Raymond's crystal radios are a great starting point: www.ebay.com/s...
#1N43A
#CrystalRadio
I said "graphite" instead of "ferrite" at least once. Ferrite bar is what you want.
Electrical outlets screw.
Perfect, thanks for the tip.
Thank you so much!
Note that in some old houses this won't work and also on some very new ones.
On old houses there was no ground in much of the wiring
On new houses there is a ground but the screw is insulated.
if you have a mattress, esp a double, with interconnected springs in it, try clipping onto the springs as an antenna, can work really well.
Also, you want a high Q coil if possible, so either a ferrite rod with litz wire or some kind of air litz coil in spider or basket.
If you make a loop coil combined antenna you can get good reception from 3-4 feet a side, but it will be strongly directional. what you can do is put four nails in the outer corners of a wood door and wind maybe 4 turns and use that as your main coil, open and close the door for pointing the antenna. Any wire will do, but better not too thin. No antenna required, the coil is the antenna.
I've found germanium diodes are not everything, 1n418 can be good.
A lot of people may have difficulty getting a good variable capacitor, you can use a variable inductance by sliding the ferrite core in and out of the coil, put a fixed 100 to 200 pf capacitor across the coil, or switch a few fixed caps to minimise the range of inductance needed.
You can also make variable inductance by sliding two coils in and out of each other, coils must be wound in opposite directions.
That’s really cool Paul!
Yeah I can see you digging this kind of project. It's pretty satisfying.
That's very nice Paul! I remember of my first crystal radio built in the early 60-th (past century of course)HI!. Thank you again!
We had to place THE BELL again - as there was no notifications with subscription and Bell On from youtube about your chanel! Happy New Year!
Thanks, YT has suspiciously throttled my channel the last few months 🤨
Just checked the outlet I intend to use, it’s properly wired and grounded 👍🏼.
I really didn’t want to run a wire to a cold water pipe.
Thanks for the tip. 👍🏼🙏🏼
For me the outlet screw worked better than the pipe, 15' away from my radio. Just be careful not to put wire, screwdriver etc into outlet holes.
For more modern houses, the water pipe inlet is PVC or similar. So using a copper pipe in the house won't really give you a ground at all. Outlets work because the ground connection on the socket and the outlet body are connected to an earthing system.
Thanks for this.. very enjoyable.
Hi Paul, great stuff! Have you considered a compact multi-turn loop antenna to get more stations? Regards, Niels
Thanks for watching Niels. I've experimented with loops and Archimedean spiral antenna on cardboard which performed about the same as wire across the room. I really need to get the wire outside, but that's tough in my apt. bldg.
Amazing rig, sir.
Very informative. Built my first last week using old capacitors sourced on ebay. Now building a tube amplified version next - a kit supplied by Borden Radio.
Sounds like a great project. Post back how it goes.
Looks like the last couple plates on the rotor are very close. When tuning down, they could be shorting on the stator plates, causing you to not pick up the lower stations.
Thanks, I'll check that out & bend the last plates out so they're not touching.
i live in an upstairs apartment, our water pipes are pvc . thanks
Hi!
Just curious as to what you are using for a ground?
Thank you
John
I'm in a 3rd story apt so ground wire goes to electrical outlet screw. An earth ground & 50' antenna would be better! Good luck.
Hey Paul, can you try to connect this output of the crystal radio to input to old CRT TV and see what kind of picture you get :D
I'm guessing static?
Just wondering are you sure it should be graphite.. Thought it should be Ferrite?
Yes you're right!
A network engineer friend has access to the old ethernet cables that are removed and scraped and I have a nice tree about forty feet from the house.
Can I use the old ethernet cable for an antenna? Without removing the insulation? Does it need to be a specific length? would several passes be better? Would soldering all the pairs together at each end be helpful?
Thank You
I use old cat-5 cable for ham band TX/RX antennas and it works fine. Stripping and connecting together all 8 wires is only necessary at the feed point(s); not needed on the other end.
@@ernestsmith3581 THANK YOU!
Thankyou
I would expect that if you built a mag loop receiving antenna and if you did nothing other than just close couple it to your receiver you would receive much more than by only a 10 foot piece of wire.
To have a resonate half wave dipole that receives well in the 160 meter amateur band aka roughly 1.8 Mhz it needs to be roughly 264 feet long. Ten feet is only going to receive a very strong local station and no DX.
Try the Mag Loop. If you can't physically connect it to your crystal set just place it roughly 5 to 10 inches away from it and tune it too. You likely will be shocked by the difference.
Yes I should make a tunable loop antenna. I've tried passive loops and spirals with no difference. Perhaps I can connect 1 gang of my 2 gang capacitor to tune the antenna, and the other gang to radio.
@@p1nesap Well, here is the thing.
For a receive Mag Loop you make an inductor which can be X turns around the perimeter of a cereal boxe's perimeter or even a frame made from 1 by 4 lumber. You calculate or actually measure the inductance of the loop and from that you size your capacitor so that the LC circuit you create resonates in the range your aiming for. After this you can either just close couple the new LC circuit to your radio or add what is called a sense which is one or two loops around the other bigger loop with one end connected where the antenna connects and the other to your sets ground.
The issue you would have using the second gang on your tuning capacitor is its pretty unlikely where it needs to be rotated for the radio matches where it needs rotated for the mag loop antenna.
I get a lot of my variable capacitors from buying radios from the 70's that are almost given away in a Thrift store. You will likely need up to 375 or roughly 500 pf which all the old tuning capacitors are depending on using both or one gang.
I just recently bought a high voltage 8 to 48 pf variable with gear reduction for $22 for a four foot square Mag Loop antenna I made for transmitting on 20 meters or around 14 Mhz. I built it for efficiency where it outputs 79% of what is input. Thats why the main loop is 4 inch aluminum dryer vent and the sense is 3/4 inch copper pipe.
For receive only using just wire is good enough because you dont have to impedance match else destroy your power amplifier.
You can also use the tiny variable capacitors that were in transitor radios as the tuning capacitor because your not transmitting so there is no danger of arcing. These I buy on Ebay too and they are maybe $5 each. I made several receive mag loops with them and they work great. I forget what their name is but they are about 1.25 inches square and about 3/4 inches thick. They typically have a plastic case often clear on one face and they too have two gangs that can be used in parallel.
Lastly say you find a great 350 pf variable, but it only gives you the upper range aimed for. The simple thing to do is add in a fixed capacitor in parallel that is big enough to boost the total to what is needed. Additionally as a side note, to get finer tuning on your radio add a small, like 0 to 30 variable cap, with gear reduction if possible, in parallel with your main tuning cap. This makes fine adjustments so much easier.
Good luck. You will be amazed at the difference. Try to make your mag loop at least 16 inches in height and or lenght. The bigger the better sensitivity. A 2 foot square does extremely well but even the 16 incher does great.
Before I forget there is a channel on UA-cam & I think its galled Gaslinger or similar. It is a great resource for all thongs radio and there is a video I just saw where he or she compared various diodes for suitability in a crystal set. Obviously there is the 1N34A but almost as good are pretty much all the other germanium point diodes such as the 1N270, 1N160, 1N182, CK706, but of real significance is she or he showed you can forward bias a Shockey Silicone diode with a small voltage and it will be every bit as good a detector as the 1N34A.
Its a lot of fun for sure especially when you start picking up the other coast at night on your crystal set. Have fun & go for it, plus find a good resource on building the first time for reference. I used to know of one, but forgot the source however a UA-cam channel I think called Solder Smoke probably has a good build in it & if not I know they are out there.
73
kc2wvb
Most likely the other side band .
Smaller circuitry isnt always best in my opinion . Old school radios thats have lasted 100+ years and bulky and easy to fix