quick advice please

[ridgescan]

I got you N Jay-the whole thing is unfortunately you aren't right here with me experiencing the vast improvement on that damm thing-all I can do is film a 45 secon quip because stupid photobucket only allows 100 MBs at a time. If you were here you would be impressed I think.
Anyways I wound up getting a new Diamond for the scanners so I'll have two up there

...after just reading Warren's post above-I think I had better clarify something; when I said to N Jay "the whole thing is unfortunately you aren't right here with me" I meant "you aren't right HERE in the same room hearing what I am hearing" I hope that clarifies because I appreciate the stuff he has said here. Warren-you don't need to bust my balls like you are-switch to decaf pal but DAMM you are so good with this stuff we are lucky to have you here! I actually tried that unscrewing the outer dealie and just leaving the main pin inserted-I got mostly noise and a slight increase in carrier...plugged it all the way in and screwed it tight and the whole signal gets super clean and steady.
Mike-thank you so much for the time and effort you put into helping me understand what's going on here and doing so without an ounce of arrogance. I am re-reading your efforts here and also thanks for the PM offer-I will.

 

[ridgescan]

Hi Mike, I did this video for you guys to see what happens when I do the test. My antenna is about 20 feet from high power lines and about at the same height. Sorry about the shortness of the video. Anyways as you can see, lots of noise happens both with the outer jacket connected AND, if you can notice, as I am plugging the pin just before the outer jacket hits, but when the outer jacket is connected, you have the clean steady signal. What does this say about the "setup" now that you saw this? When the outer shield is "acting as the antenna" in my case all I get is lots of noise. Once the outer jacket is properly connected to complete the "setup"...to me it seems that the outer shield is now doing its intended job?? Is my line acting as the antenna? This is why I am confused.

 

[ridgescan]

...so no feedback? Here's another with a different station 12 hours later. In this video I let it speak for itself. I hope these videos show you guys why I am confused by what you say. If the outer shield becomes the antenna via either the jacket wire or by just inserting the pin with no ground-I get mostly noise and uneasy signal. So what is cleaning up that signal so well when the coax is plugged and screwed proper? I can't help but think that once I connect that outer jacket and that signal cleans up, the coax shield is doing its job. Since there is no more noise at that point, but there WAS noise, and plenty of it, when I used the coax shield as the antenna then is that shield acting as the antenna still? If it is acting as the shield then what is doing the recieving if not the discone-at least to some extent? HELP!!!

 

[Mike_G_D]

Hey ridgescan,

Unfortunately, I have a very slow internet connection and videos take forever to download for me. Still pictures would be better. Having said that, based on what I do see from the first frame of video in your post I think you basically got the point with the exception that, when using the shield, try and ground the SO239 connector outer shield on the the R75 to earth if at all possible.

Anyway, I have some other comments and questions.

First, I see some spring clips on the back of the R75 near the SO239 connector. If those are for a wire antenna connection then I would use those to connect to the outer shield rather than the SO239. Connect the outer shield of the coax to the RED spring clip and connect the black clip to earth ground if at all possible. To add, I just downloaded the manual to the R75 and those clips are for a wire antenna. They are selected via the front panel antenna selector switch and are designated as "ANT 2".

Also, what frequencies are you looking at to test this? If you are looking at frequencies in the 25MHz range then you may see what you are describing because the discone might marginally work on those frequencies. I would use much lower frequencies such as around 5MHz or so. Try using the 5MHz WWV time signal as a gauge and do this at night as the lower frequencies propagate better at night.

Test in the following configurations:

For all tests use a low frequency (lower than 15MHz) and test at night. The WWV 10MHz and 5MHz signals are good choices but you can try any constant broadcaster. Try several different ones and record quality for each (in writing not by video).

1) Normal, that is with ANT 1 selected with the front panel selector switch and the coax completely connected to the SO239 connector on the R75 (just as you originally had done).

2) With the ANT 1 selected and the shield unscrewed but center pin connected (as Warren suggested) on the SO239 of the R75.

3) With ANT 2 selected with the front panel antenna selector switch and with the center pin of the coax PL259 connected via a short wire to the RED wire antenna terminal of the R75 and the black terminal grounded (NOT to the coax shield but to earth if possible; use a cold water pipe if you really can't get to earth ground).

4) Same as number 3) above except using the outer shield of the coax connected to the RED terminal rather than the center pin. Just as in #3 the black spring clip is grounded to earth or to a cold water pipe.

Now for some more questions from me.

1) Exactly how do you have the discone mounted? I take it that it is mounted outside on a mast. Is that correct? That is how I have been visualizing it and is how I have been analyzing it to date. If so, is the mast metal and is it grounded itself (either by being mounted in the ground or by being grounded via grounding wire(s)?

2) Do you have two lengths of coax running up to the roof? You mentioned that you were using the discone for your scanner and a 2 meter Yagi for your R75 so I am assuming that you have two lengths of coax running up to the roof - one connected to the Yagi and one connected to the discone. Is that correct?

3) You say that you have no room for a long wire but do have room to put up two discones since you mentioned that you were going to purchase a second discone for the R75. So you have vertical space for antennas but not horizontal space, is that correct?

4) Why do you have the 2 meter Yagi? I am assuming you did not purchase it for use with the R75 originally. Are you a Ham and use 2 meters or used to?

If possible provide a clear STILL picture of your outside antenna arrangement. Show shots of how the antenna is mounted on the mast and how the coax is connected and run into the house. Do this for both the Yagi and the discone.

Finally, if you have access to a multimeter, disconnect the coax running to the discone from the radio and measure continuity between the shield and the mast (if it is metal) that the antenna is mounted on. Next do the same for the Yagi. Record and relate the results.

-Mike

 

[kb2vxa]

Ridge, I'm not busting your bees, just fed up with your argument. NOW the scenario changes a bit with this new information, still I think there is discontinuity but it's possible location has changed. The reaction you saw tells me it may be on the other end, at the antenna which would make the entire antenna and support structure an active element. You can run a simple contenuity check but how you do it depends on a particular factor.

Is the structure grounded for lightning protection? If so all you have to do is connect an ohm meter on a low range scale, say RX10 between the shield and anything grounded. The reading doesn't matter, only that there is a reading, if there isn't the shield is an open circuit. If the structure is not grounded you'll have to find a way to connect the meter end to end on the coax, run a temporary wire or best yet, take the coax down and check it. That will give you a great opportunity to check the condition of the coax, connectors and antenna, there may be corrosion which can easily disrupt the whole affair. Oh and while you're at it check for squirrel damage on all exposed areas of the coax, another likely possibility. Overlook nothing, you'd be surprised where those nasty little buggers can get at.

The bottom line is the active elements of a discone or any other VHF antenna are far too small to be effective on HF. Oh sure you may hear SOMETHING but rather weakly, certainly not IMO as well as you say. In any case I only try to help so please don't bite the hand that feeds you, my response was to the pain you inflicted. Now do like Larry says and git 'er done, I'd like to see the results of your inspection. If everything is well, in order and nothing wrong, well hush my mouth, I'm faced with another of life's little mysteries.

 

[ridgescan]

Here's a pic of it-it is mounted on an aluminum vaacuum cleaner extention pipe (don't laugh-they are strong as hell and it's been there for two years) which is harnessed to an aerator pipe on the roof with hoseclamps-NO lightning ground. The coax goes up the steel mounting tube and a pl259 screwed into the antenna (nice and protected)

 

[ridgescan]

...this is the "holy grail" of vidoes gentlemen J/K but it does go to show that the discone IS actually doing the recieving. Anyone still skeptical? To all here who posted to say there was NO way that antenna was doing a lick of work-I am a mental midget compared to you guys-but I was NOT lying to ya. Dare I say again that this could offer a solution for space challenged HF lovers?

 

[W6KRU]

Hi Ridge! I haven't butted in here as more knowledgeable people than me have been involved. But I gotta say at this point I am skeptical of a antenna receiving very well outside of it's specs because if it was capable of doing that, the marketing guys would certainly include that info.

I would like to see an A/B test with an 80m dipole and the discone. That would seal it for me but I realize that is not that easy to do in some environments.

 

[ridgescan]

Hi Ridge! I haven't butted in here as more knowledgeable people than me have been involved. But I gotta say at this point I am skeptical of a antenna receiving very well outside of it's specs because if it was capable of doing that, the marketing guys would certainly include that info.

I would like to see an A/B test with an 80m dipole and the discone. That would seal it for me but I realize that is not that easy to do in some environments.

No I totally agree especially after my eyes were opened in this thread by Mike G D, Warren, and N Jay. I pissed these guys off by saying it did an "awsome job on HF". What it did do to make me say that, is clean up the noise floor and give me more reliable signals compared to any antenna I have used before it. This is pertaining to MY application in MY situation, along with apparently being in the right area for reception.
The whole bottom line to starting this thread is that I was HAPPY with that, and was not bragging the antenna up. Sorry about my poor choice of words in the OP. Since I cannot do longer videos I cannot really set there and tune the spectrum and show you guys all the stuff I get from just above MW all the way up on to 21-30 with OUT the horrible noise I was getting before. Freeing up from noise means more to explore man! These gents (all of whom I greatly respect) were saying the antenna was doing NOTHING (but N jay DID say possibly the whip part as did Warren later)-I am pretty confident my last two videos proved otherwise.
I have to say again Dan-I've got several videos out actually showing what kind of reception this thing is getting. You can see for yourself. Hell-if you want, I have NO problem logging DX here with video...every time I catch a DX like that BBC transmission to Asia via Singapore-I can put it here for you. How about those hams on 160 meters? People here were telling me there is no way this antenna could go that low. It did-look at the video! I got a guy who told me in a PM the videos are "meaningless"...but, according to him, he has trouble downloading them so he maybe hasn't seen them. I was told that the discone would never recieve on hf-yet the two videos above show it with a small 3' section of coax, in my bedroom, on the floor, without a mast or lightning ground, DOING THE JOB!
.....I haven't even started showing you how it does on MW maybe you don't wanna see that. I will show you another VOA broadcast to china via the Phillipines instead

 

[ridgescan]

*bump*^^^^^check out the videos I would LOVE to hear others' reception and whatever antennas you are using!!! Where are you guys?

 

[ridgescan]

Still nobody willing to acknowledge that the discone is recieving HF and quite well considering it is indoors, on my carpet with no mast-with just over 2' of coax? Where are all you guys who thought I was making up a "myth"? I am still waiting, but not holding my breath.

 

[W6KRU]

Still nobody willing to acknowledge that the discone is recieving HF and quite well considering it is indoors, on my carpet with no mast-with just over 2' of coax? Where are all you guys who thought I was making up a "myth"? I am still waiting, but not holding my breath.

Hi Ridge! Every now and then the blind pig will find the acorn in the bottom of a mud hole. :lol::lol: I am a licensed ham and I can tell you that propagation is more important than anything else in receiving HF freqs. With good propagation you can receive signals with stuff that doesn't work well. I have an ft857 in my Bronco hooked to a hamstick antenna clamped to my spare tire carrier. Most knowledgeable people will tell you that this is a seriously compromised setup. Yet, last summer I had solid contacts with several operators in Argentina and Brazil from my driveway here in Oceanside, CA over a 2 week period. I couldn't do it right now if my life depended on it. It's all about propagation sometimes.

 

[ridgescan]

Hi Ridge! Every now and then the blind pig will find the acorn in the bottom of a mud hole. :lol::lol: I am a licensed ham and I can tell you that propagation is more important than anything else in receiving HF freqs. With good propagation you can receive signals with stuff that doesn't work well. I have an ft857 in my Bronco hooked to a hamstick antenna clamped to my spare tire carrier. Most knowledgeable people will tell you that this is a seriously compromised setup. Yet, last summer I had solid contacts with several operators in Argentina and Brazil from my driveway here in Oceanside, CA over a 2 week period. I couldn't do it right now if my life depended on it. It's all about propagation sometimes.

Hey Dan propogation or not, that discone IS doing the work. THAT is my point. Lousy propogation can screw up a longwire too. These guys came in here after I said I was happy with what I had and flat out said there was NO WAY that discone was doing the work. Several videos later proving it IS, and nobody will at least acknowledge that it is recieving HF. The one on the roof gets tons of stuff, DAY AND NIGHT, throughout the bands-I have several videos here that clearly show that too. I am a little sore that they slammed me pretty good then when those videos showed up they got pretty quiet.
Bottom line-their beef with me was that there was no way the discone had anything to do with my getting HF even with great propogation-they insisted that it was the line OR the pipe OR the mast OR the whole thing. My most recent video above pretty much KILLS that. They accused me of creating a "myth"-the videos don't lie. That is why I posted them. I didn't start this. Now Dan, please don't tell me that after seeing that discone recieving HF on those videos, you too are refusing to acknowledge that it did too.
They accused me of being "one so not willing to learn" when all I was trying to convey to them was that the antenna was doing the job-so I let the camera do the talking instead.
Lastly, Dan, I experience plenty of lousy propogation here, especially during midday and late afternoon-but I still get quite a bit then too.

 

[W6KRU]

Ridge, What would you think if I threw up a post based on my experience above and stated that my hamstick on the back of the Bronco was all of the antenna that was needed to work the world and that the buffoons who were using those big beam antennas on the towers with rotators were wasting their time and money? I could have videoed the contacts with Brazil and Argentina as proof of my point.

When the sunspots return you won't need anything as elaborate as the discone. A simple piece of wire shoved into the center of the so-239 on the back of the radio and laying on your floor will work.

A proper is antenna is a proper antenna and anything less is not. I wish it was as easy as throwing up a discone. HF would be so much easier.

The fact that some of those trying to help you earlier are quiet now might mean they threw up their hands and turned their backs on you. I came in later and have a little patience left.

 

[ridgescan]

Ridge, What would you think if I threw up a post based on my experience above and stated that my hamstick on the back of the Bronco was all of the antenna that was needed to work the world and that the buffoons who were using those big beam antennas on the towers with rotators were wasting their time and money? I could have videoed the contacts with Brazil and Argentina as proof of my point.

When the sunspots return you won't need anything as elaborate as the discone. A simple piece of wire shoved into the center of the so-239 on the back of the radio and laying on your floor will work.

A proper is antenna is a proper antenna and anything less is not. I wish it was as easy as throwing up a discone. HF would be so much easier.

The fact that some of those trying to help you earlier are quiet now might mean they threw up their hands and turned their backs on you. I came in later and have a little patience left.

1. I know a proper antenna is a proper antenna.
2. I know I am using an antenna that is totally NOT designed to recieve HF PROPERLY.
3. I am putting the discone to use on th R75 simply because I do not have the space for the PROPER HF antenna-NOT EVEN 20'!
4. The discone is GIVING ME WHAT I NEED on HF.
5. Reread my answer to you in my last post. You are missing my point which is they refused to acknowledge that discone was recieveing hf-I am NOT saying that antenna is the proper antenna for HF.
6. I tried a simple piece of wire AND the 20' coax shield AND a whip antenna too and all of them gave tons of noise while the discone gives me a clean quiet signal. You just got done telling me that it's all about propogation-so if that is the case here, then why does the discone work better than them?
7. You are annoyed because these are your buddies-hell, you have an N Jay quote in your sig. I do NOT care if you turn your back on me too. Facts are facts. The videos don't lie. I still enjoy the heck out of what that antenna brings no matter how you feel about it.
8. You said you worked somebody far far away on a POS antenna for two weeks. I assume that is a fact. It is no different than my situation.
9. I never said all those guys with all the big fancy antenna were wasting their time and money, NOR is my saying I am HAPPY with what I have inferring that. You are embellishing.
That is all I am going to say after this-I posted LOTS of videos showing its performance, I NEVER said it was "the proper antenna"-I just think that after I SHOWED what this thing does, nobody is willing to say "well Ridge that damm antenna sucks but hey if it works more power to ya"-instead they got all judgemental and condescending-NOT COOL. You, just like your buddies, STILL haven't acknowledged what the videos clearly show, proper antenna or not that is just you being close-minded about this matter, so whatever.

 

[prcguy]

I think too many people here are forgetting that HF reception is limited by signal to noise ratio. In many if not most cases if you have a certain SNR on an HF signal, going to a larger antenna, be it resonant dipole, random length wire, etc, the signal at the receiver can increase but so will the noise by the same amount.

Go the other direction to a smaller antenna and the signal at the receiver gets weaker but so does the noise. In many cases a very small antenna like a VHF/UHF Discone can provide more than adequate signal level and there can be little or no noise if the SNR is high to start with. It can be much quieter than a random wire attached to the back of a radio because it probably won't pick up as much RF EMI from inside the building.

I pick up plenty of HF on a VHF/UHF Discone and sometimes its more pleasant on the ears because the noise floor is always so quiet. I can get a similar result by switching on the attenuator or running up the RF gain when using my 102ft G5RV but sometimes the Discone is the winner.

Is anyone who is questioning what Ridgescan is claiming actually duplicating the setup and trying it? I have and it works ok. If I was not able to put up large HF antennas where I live I would make do with what I could get away with and maybe that's what Ridgescan is doing.
prcguy

 

[ridgescan]

I think too many people here are forgetting that HF reception is limited by signal to noise ratio. In many if not most cases if you have a certain SNR on an HF signal, going to a larger antenna, be it resonant dipole, random length wire, etc, the signal at the receiver can increase but so will the noise by the same amount.

Go the other direction to a smaller antenna and the signal at the receiver gets weaker but so does the noise. In many cases a very small antenna like a VHF/UHF Discone can provide more than adequate signal level and there can be little or no noise if the SNR is high to start with. It can be much quieter than a random wire attached to the back of a radio because it probably won't pick up as much RF EMI from inside the building.

I pick up plenty of HF on a VHF/UHF Discone and sometimes its more pleasant on the ears because the noise floor is always so quiet. I can get a similar result by switching on the attenuator or running up the RF gain when using my 102ft G5RV but sometimes the Discone is the winner.

Is anyone who is questioning what Ridgescan is claiming actually duplicating the setup and trying it? I have and it works ok. If I was not able to put up large HF antennas where I live I would make do with what I could get away with and maybe that's what Ridgescan is doing.
prcguy

I gotta say thank you prcguy-the way you describe it...BINGO!! That is all I am saying-I don't know how many times I have said throughout this whole thing and in other threads that it gives me a clean quiet RELIABLE signal-what more could you ask for?

 

[specman]

Well hey, if you're happy then good for you. I tried a similar setup once and it didn't peform well, although it was better than no antenna.

Cheers

 

[prcguy]

It depends a lot on the coax run. At HF, the top of a Discone or even the little whip is very high impedance and a long run of coax will have additional loss over what the factory specs show.

Many active HF antennas are E-field type and are nothing more than a very short whip with an amplifier at the base configured to match the very high impedance whip to coax with little if any voltage gain. My AMRAD active 1m long whip can sometimes outperform a full size resonant dipole or G5RV on HF and on VLF the active 1m long whip usually wins.

That's because its up in the clear and subject to the same signal to noise ratio as the full size antennas. The G5RV has big problems at VLF where the active antenna is operating inside its design parameters. The 1m long active antenna can also provide less interference than my full size antennas because they are above the entire house with all of its built in noise making computers, switching power supplies, etc where the active antenna is remote at the far end of the property and subject to less house grunge. Similar results can be had using various types of VHF/UHF antennas for HF receive.

I say everybody reading this thread who has a Discone and an HF receiver should try the Discone and honestly report what you find. Don't just assume and give an opinion.
prcguy

Well hey, if you're happy then good for you. I tried a similar setup once and it didn't peform well, although it was better than no antenna.

Cheers

 

[specman]

I say everybody reading this thread who has a Discone and an HF receiver should try the Discone and honestly report what you find. Don't just assume and give an opinion.

I can say I have tried such a setup and was dissapointed. No surprise in my opinion. The fact that it receives some signals is no surprise either...so if the OP is satisfied with what he hears then good for him.