how likely is a bad Antenna?

[FCVPI99]

That much gain would be a directional antenna. You'd be looking at a log periodic design or a Yagi design.
There are vertical antennas that will give you 10dB of gain, but those are very large antennas and usually up in the higher bands.

ok how about 7DB since i did just fine this about the 1 footer ant's this was berried all the way at the bottom .. i fig bigger ant of the same type might bring in the few towns im trying to get still

 

[FCVPI99]

Yes, that would be a good test.

You'd still want to make sure no part of the antenna was touching metal. I'm thinking you had someone install this for you, are you confident they did it correctly?

no i did it ... being its almost 8 foot tall i was able to grab the very tippy top wile laying down in my front and pull it up the opening ... but to get it down it has to go the same way top first so getting it down would be 2 man

 

[FCVPI99]

Yes, that would be a good test.

You'd still want to make sure no part of the antenna was touching metal. I'm thinking you had someone install this for you, are you confident they did it correctly?

ok i take my new old stock analog 22-203C tester i just got red to center pin black to outer section and it doesnt move at all ... from what i have found out it should move all the way to 0 as it did when i checked the LMR 400 coax pin to pin and outer to outer

 

[mmckenna]

ok how about 7DB since i did just fine this about the 1 footer ant's this was berried all the way at the bottom .. i fig bigger ant of the same type might bring in the few towns im trying to get still

That 1 foot tall antenna does NOT have 7dBi of gain from 20MHz to 1300MHz in any universe or by any stretch of the imagination. That's pure USDA Grade A Bull****.

If you want a high gain antenna, you'll be looking at single band, so we'd need to know what band you were interested in. High gain (7dB) multiband antennas are going to be very large, or something big like a log periodic that will not fit in your attic.

 

[mmckenna]

ok i take my new old stock analog 22-203C tester i just got red to center pin black to outer section and it doesnt move at all ... from what i have found out it should move all the way to 0 as it did when i checked the LMR 400 coax pin to pin and outer to outer

Full needle swing would be a dead short, which you don't want on a discone when checking from the center pin to the outer shell of the connector. If the needle isn't moving, then there is more testing to be done, but it's not showing a short between the center conductor or the outer shield. Might still be an open at the antenna.

 

[FCVPI99]

Full needle swing would be a dead short, which you don't want on a discone when checking from the center pin to the outer shell of the connector. If the needle isn't moving, then there is more testing to be done, but it's not showing a short between the center conductor or the outer shield. Might still be an open at the antenna.

are you sure cuz again everything i have seen and know says you want 0 ohm, 0 ohm is good anything above 0 is bad

 

[mmckenna]

are you sure cuz again everything i have seen and know says you want 0 ohm, 0 ohm is good anything above 0 is bad

Are you looking at the top Ω scale on that meter?

0 ohms is a dead short. You absolutely do not want a dead short between the center conductor of the coax and the outer shield with no antenna or radio connected. If it is showing 0Ω, then you've got a short, likely in one of the connectors.

 

[FCVPI99]

Are you looking at the top Ω scale on that meter?

0 ohms is a dead short. You absolutely do not want a dead short between the center conductor of the coax and the outer shield with no antenna or radio connected. If it is showing 0Ω, then you've got a short, likely in one of the connectors.

0 ohms means there is no short as per ever single vid from all the ham guys showing how to test coax on youtube

 

[mmckenna]

0 ohms means there is no short as per ever single vid from all the ham guys showing how to test coax on youtube

No. Zero ohms is a dead short, no resistance. If you are reading 0 ohms from the center conductor to the shield, then you have a short between the two, and that's bad.
You can confirm this by setting your multimeter to the Ω setting and then touching the two leads together. The needle should swing all the way over to the right and land on zero (or very close, depending on how your zero adjust wheel is set).

With the coax disconnected from the antenna and from the radio, there should be no connection between the center conductor and the outer shield of the coax. Meter should show ∞Ω, or the needle all the way over to the left.

 

[mmckenna]

0 ohms means there is no short as per ever single vid from all the ham guys showing how to test coax on youtube

I think you are misunderstanding what they are saying. Hopefully no ham would think that 0Ω is an open. But I've seen quite a bit of incorrect info on YouTube.

 

[prcguy]

I would not only test the coax for no short between the center and shield, then for a short between the center of both connectors, I would also test across the antenna connector on the Discone. It should test open or infinite resistance like the center to shield of the coax.

 

[G7RUX]

Take the meter, put it on the low ohms range and connect the probes together, this should give zero ohms/short circuit. You may need to adjust the “ohms” wheel on the left to get zero. Remember that the meter should be on the infinity mark before you short the leads; adjust with the screw in the centre of the meter movement to get the meter zeroed properly.

Connect the meter to the inner and outer and you should see no deflection on the meter. Some antenna types will show a DC path but a discone should not.

Assuming no deflection, disconnect the antenna and connect a wire across the inner and outer at the antenna end…you should now see a dead short; zero ohms, or thereabouts.

At this point that is pretty much as good as you can do with testing coax with a multimeter; here you should have shown no DC path between the inner and outer but also continuity through the connector outer, into the screen, up the screen, through the top connector back into the centre conductor and back down again.

 

[FCVPI99]

screw it ... being im getting conflicting info who wants to make some money and go up into an attack and test some stuff ????

 

[FCVPI99]

so this is the 1 foot ant that works great just trying to get another few miles in distance

 

[prcguy]

screw it ... being im getting conflicting info who wants to make some money and go up into an attack and test some stuff ????

Fly me there and back from So Cal and I’ll find the problem.

 

[FCVPI99]

this is the discone - black line is coax white line is make shift ground the pic the one with the coil of coax is where i go into the room
i have retested the coax 0 on center to center and 0 on outer i think i tested the ant right again i cant move well and it didnt move the needle at all

 

[FCVPI99]

Fly me there and back from So Cal and I’ll find the problem.

thats now how jobs get paid

 

[mmckenna]

screw it ... being im getting conflicting info who wants to make some money and go up into an attack and test some stuff ????

You are not getting conflicting info here. I suspect that some of the YouTube videos are not very clear, or the people making the videos do not understand what they are talking about. Remember, anyone can make a youtube video. Being a ham doesn't imply any sort of expertise or experience, either. It just means they passed a multiple choice test at some point in their life.

Hard to see much in those photos. I wish I was closer and I'd be happy to help you out.

 

[G7RUX]

so this is the 1 foot ant that works great just trying to get another few miles in distance

To be honest I cannot see the antenna in this one.

In general a discone will give reasonably good performance across a fairly wide frequency range so I would be very surprised if a “one foot” antenna gave better results. I may have missed this but what sorts of frequencies are you looking to receive?

Oh, I don’t think I would suggest grounding the antenna if it’s installed in the attic.

If you are receiving OK with the short cheapie but not with the discone then I would wager money there’s something amiss with the antenna; it may be incorrectly assembled or there may be a problem you can’t see. Did the antenna arrive with the hub assembled?

If the coax is ok (and it sounds like it probably is) then I’m perplexed as to why you’re not receiving anything of note on the discone. Trying to receive a local VHF amateur repeater, or enlisting the assistance of a local radio ham with a VHF handheld might be the way to go…check to see if there’s a club local to you that might be able to help. Generally hams are helpful people and should get you sorted.

 

[PDXh0b0]

Cheap test..get an F Female to UHF Male PL-259 adapter and and f-type to whatever you scanner connector is and try some rg6 between the two.

I purchased some lmr off Amazon, both times I had to re-solder the connectors. I'm DX only, I use rg6 on 8 of 10 of my antennas