Whatever Happened to Ham Radio?

[KF5OBS]

They didn't even bother to clip the braid off, and any of the little wires could touch the antenna and short it to ground, thus ruining even the minimal effectiveness of the things. 

Wow. Just wow.

[DL8RI]

We experimented with one today too.
Because a Radio-Transmitter is on the building next to us, 2m was not really receivable... we build this very... erm... "ham-like" filter today:

Quick and (very) dirty, but it worked.

[xrunner]

We experimented with one today too.
Because a Radio-Transmitter is on the building next to us, 2m was not really receivable... we build this very... erm... "ham-like" filter today:
Quick and (very) dirty, but it worked.

Cool. Boy that web page has some pretty ... interesting ads to look at. 

[Lurch]

Boy that web page has some pretty ... interesting ads to look at. 

Ads?

[lemmegraphdat]

Just contacted W1AW on 17m operating from N. Carolina. 

Anyway, some local hams and I are using the DVB dongles as SDR radio receivers. What they are marketed for is as a TV receiver for your computer. Since the antenna is basically a piece of junk as far as using it for ham applications, I just cut it off and put an SMA connector on the cable so the cable can be used to connect the dongle to a ham-it-up up converter (the other end has the required MCX connector that fit the dongle ant. connection).

Well two of the guys gave me their antennas to put SMA connectors on, and I thought it would be interesting to see how the assemblers in China did their work inside the base. It wasn't pretty.

They didn't even bother to clip the braid off, and any of the little wires could touch the antenna and short it to ground, thus ruining even the minimal effectiveness of the things. 

What's the difference between that and having an antenna ground? One of Marconi's contributions.

[xrunner]

What's the difference between that and having an antenna ground? One of Marconi's contributions.

I do not understand your question. Please re-phrase.

[GreyWoolfe]

Ads?  I didn't see ads, just boobies

[lemmegraphdat]

What's the difference between that and having an antenna ground? One of Marconi's contributions.

I do not understand your question. Please re-phrase.

Having the antenna grounded was an improvement that Marconi came up with. The ground makes the Earth a capacitor. So having the signal grounded means that energy is stored. This goes into the radio through a matching transformer. Improved signal strength.

[Rory]

Having the antenna grounded was an improvement that Marconi came up with. The ground makes the Earth a capacitor. So having the signal grounded means that energy is stored. This goes into the radio through a matching transformer. Improved signal strength.

Please show us the source of this information?

[DL8RI]

Having the antenna grounded was an improvement that Marconi came up with. The ground makes the Earth a capacitor. So having the signal grounded means that energy is stored. This goes into the radio through a matching transformer. Improved signal strength.

Maybe I misunderstand you, but a short in the foot of the antenna will cause a maximum of mismatch and therefore make it impossible to get energy in or out of the antenna because more or less everything is reflected.

Do you maybe mean using the ground as counterweight?

PS: I'm sorry, if there were disturbing or whatever irritating ads on this Homepage. I use this hoster for several years now (and have therefore my pictures "under control") and never really looked at the ads, and now I'm using adblock to be able to use the internet at all.

[GreyWoolfe]

DL8RI, did you mean counterpoise instead of counterweight?  Counterpoises allow, correct me if I am wrong, capacitive coupling to the earth, which I believe creates a massive ground plane and will give the signal a lower angle of take off which is good for DX contacts.  When using unbalanced line (coax) everyone seems to call the shielding the ground side.  The shield shorted to the conductor  in coax, will provide an infinite swr to the radio and either cause the radio to cut back power or damage the radio.  Don't worry about the boobies, I may be married but I am not yet dead .  Xrunner, I caught him on 20 meters also.  Do you know if he is doing a QSL card?  If so, I would love to get one from him.

[xrunner]

Xrunner, I caught him on 20 meters also.  Do you know if he is doing a QSL card?  If so, I would love to get one from him.

Yep - 100% QSL, send s.a.s.e. 

[hiddensoul]

On high frequency stuff UHF VHF you don't need a huge counterpoise, you only need a metal surface a quarter wave length in size or bigger, I use a baking tray with an SO239 on it for VHF (2 meter) in the field. Also the counterpoise doesn't have to be earth a dipole is a balanced antenna with one side being the counterpoise to the other, the dipole ideally should be at least 1/2 wavelength above the ground.

[GreyWoolfe]

X, is that to his personal call or to W1AW?  I am thinking his personal call.

[xrunner]

X, is that to his personal call or to W1AW?  I am thinking his personal call.

I would think to W1AW, that's where I sent my QSL when I contacted W100AW. The station today was W1AW / 4 operating from N. Carolina.

[GreyWoolfe]

Hidden, I agree on the VHF thing.  I wasn't talking about a dipole, I was talking about an HF vertical.  I guess I should have provided more info on my thoughts.  Just like you are talking about the 1/4 wave ground plane for the 2 meter vertical antenna.  For the field, I have a 5/4 wave vertical encased in PVC.  I shamelessly copied someone else's design and made my own modification as to the method of connection to the coax.   It mounts on a portable PVC mast system I made up and works great.  It gets used for field day and for special events communications.

Thanks, X, I will send to W1AW.  Live long and prosper with DX

[DL8RI]

DL8RI, did you mean counterpoise instead of counterweight?  Counterpoises allow, correct me if I am wrong, capacitive coupling to the earth, which I believe creates a massive ground plane and will give the signal a lower angle of take off which is good for DX contacts.  When using unbalanced line (coax) everyone seems to call the shielding the ground side.  The shield shorted to the conductor  in coax, will provide an infinite swr to the radio and either cause the radio to cut back power or damage the radio.  Don't worry about the boobies, I may be married but I am not yet dead .  Xrunner, I caught him on 20 meters also.  Do you know if he is doing a QSL card?  If so, I would love to get one from him.

Yes, that it's the correct expression. I should have looked it up before posting.
In German it means Gegengewicht, gegen= counter, gewicht = weight. Non-native strikes again.

As for the ads, if it only are some Boobs that's ok, I think. I thought it was one of the more 'advanced' stuff

[lemmegraphdat]

On high frequency stuff UHF VHF you don't need a huge counterpoise, you only need a metal surface a quarter wave length in size or bigger, I use a baking tray with an SO239 on it for VHF (2 meter) in the field. Also the counterpoise doesn't have to be earth a dipole is a balanced antenna with one side being the counterpoise to the other, the dipole ideally should be at least 1/2 wavelength above the ground.

That's cool. This is why I think some people still like radio. It's almost like magic. Techno/magician. So what you do is you lower the impedance of the antenna right?

[xrunner]

LNA for HF upconverters by 9A4QV

Another local ham got one of this guy's products - LNA for All - that starts effective operation at ~28 MHz. He's got another product now called LNA for HF that you put in front of your HF upconverter used with PC SDRs. Here's a link -

The final concept deliver 19-20dB of the gain through the range from 150khz up to 30MHz.

http://lna4hf.blogspot.com/

I ordered it yesterday and I will report on how well it works. I want to be able to see the modulation of some of the low level transmissions that I can hear on my FT-450 but cannot see on the SDR's waterfall display. The weird thing is, he asks for payment after you get the device. Wow! 

[xrunner]

Getting to be too many wires involving the sdr stuff, so I'm going to try to combine the up converter and the sdr dongle onto one assembly to reduce the wires needed as far as powering them goes. Both boards have to be connected to the PC to get power, but the up converter doesn't transmit USB data. The sdr dongle has to be connected to the PC because it has to xmit data back, so I want to snatch 5V from it's board and power the up converter from it. I hooked both of them to a lab supply and found that the dongle draws ~110 mA, and the up converter only draws ~ 10 mA. The PC USB port should provide up to 500 mA. Stay tuned.

[xrunner]

Well here's the result. It sure cuts down on the clutter.

[hiddensoul]

Well here's the result. It sure cuts down on the clutter.

Thats looks really good xrunner, nice work

[vk3yedotcom]

As far as homebrew transceivers go, I suspect that VU2ESE's Minima will be the one that finally brings multiband HF gear within the construction capabilities of the masses.

http://www.phonestack.com/farhan/minima.html



And, if anyone's wondering, it does contain an Arduino.

[Nuno_pt]

It looks very good.

It could have the speaker build in.

Nuno
CT2IRY

[xrunner]

Got the LNA for HF from Croatia yesterday but didn't have a chance to play with it. I hope to put it in-line today and see what happens.