It looks like you're using an Ad Blocker.

Please white-list or disable AboveTopSecret.com in your ad-blocking tool.

Thank you.

 

Some features of ATS will be disabled while you continue to use an ad-blocker.

 

Need Suggestions - Setting up a Shortwave Radio??

page: 1
5
<<   2 >>

log in

join
share:

posted on Oct, 1 2017 @ 05:53 AM
link   
I need some suggestions from the bright folks here on setting up a Shortwave radio receiver. I think I've got most of the right parts, but RF being as much art/magic as it is science, I need some suggestions. Principally what I need is help setting the antenna up properly (and within reason for what I'm trying to do). The set up I have works, but the reception is not ideal and I already know antenna design is the lynch pin in the whole set up.

First, here's a list of what I have to work with...

Radio - ICOM IC-R75 - Multi-band, multi-mode, commercial grade receiver with a coverage range of .3kHz - 60mHz
Antenna - (for now) LnR Precision EF-SWL HF end-fed receive antenna with a 45' radiator (with EF matchbox and end insulator)
Other - An MFJ Guardian Angel Lightning surge protector (model MFJ-270), (2) 20' lengths of pre-terminated 50 ohm RG-58 coax, (1) 100' length of un-terminated RG-58 coax and a handful of PL-259 connectors and gender-benders, barrels and couplers. Various other electrical parts.

Now, here's what I've done so far...

1. I connected a 20' length of male-male (PL-259) terminated coax to the radio. I connected the other end of this coax to the MFJ- Lightning surge protector.
2. The MFJ lightning surge protector is connectorized with female-female PL-259 connections (antenna and radio side). So I connected the MFJ lightning protector to the EF matchbox of the antenna (which is also a female) with a PL-259 (male-male) barrel connection.
3. I then connected the coax (from step 1) to the remaining female connection of the MFJ lightning protection.
4. I then ran a #12 AWG ground wire from the ground lug on the lightning protector over to an electrical outlet ground. (I did this by using a wiring up a piece of romex to a standard grounded plug, but only landed the ground wire on the plug itself (so the hot and neutral are NOT landed inside the plug)).

For the time being I strung the antenna lead on my back deck which is elevated about 8' above the ground. Because my deck is only 30' long I could not lay the entire length of the antenna straight, and had to lay the remaining 15' of the antenna at a right angle to the rest. The net result is an end-fed antenna which is approximately parallel with the ground below at an elevation of 8', and an "L" shape of 30' and then 15'. The antenna lead does not cross over itself anywhere (and the coax is also straight).

I'd like some suggestions for how I can improve reception with this set up without having to set a 50' tower or something crazy like that.

Thanks in advance!




posted on Oct, 1 2017 @ 06:06 AM
link   
a reply to: Flyingclaydisk

Listening for aliens?


www.ebay.com...



posted on Oct, 1 2017 @ 06:11 AM
link   


without having to set a 50' tower


A coiled antenna then?

or an amplifier



posted on Oct, 1 2017 @ 06:25 AM
link   
a reply to: Indigent

Don't know...looking for suggestions.

I think this antenna should work. I was picking up New Zealand yesterday during the day. I got a little bit of North Korea this morning.



posted on Oct, 1 2017 @ 06:55 AM
link   
a reply to: Flyingclaydisk

Although i'm only 10m/11m. I would say. Replace all your rg58 for rg213.
You can buy it pre plugged in various lengths.
Make sure all your plugs have a good connection.
Is the type of lightning protection essential to your system? Maybe something simpler might improve reception. I mean. Less is more. The less irrelevant things you have connected between radio and antenna. And, shortest possible route/coax.
Contradiction to above comment. You could add an external pre amp. They do drag in a bit better.
Also. Bhi speaker. They're expensive for an external speaker. And, although you're radio probably has excellent filters. The bhi speaker might just filter the reception a bit better.
Hope something helps you.



posted on Oct, 1 2017 @ 07:14 AM
link   
a reply to: Flyingclaydisk
I passed this along to my uncle, if you don't mind. He's been into short wave/ Ham radios for decades. He learned it from my grandpa.



posted on Oct, 1 2017 @ 07:22 AM
link   
So, some other questions (just thinking)...

I've grounded the antenna, so do I need to ground the radio itself also? In other words, is the antenna ground isolated from the radio chasis ground. The radio has a DC power supply (brick) so there's not really a ground connection there, per se. Should I run a separate ground from the radio chasis ground lug to an earth ground source. I read some places this will reduce interference.

Just thinking the lightning protector might have isolated the ground from the radio, hence the need to ground the radio as well.



posted on Oct, 1 2017 @ 07:25 AM
link   
a reply to: blackcrowe

The lightning surge suppressor is not absolutely required (from a physics standpoint), but everyone I talked to said not to ever set up a radio without something like this.

I'm not too worried about lightning itself (I can see when that's coming and just disconnect everything). The lightning suppression is there as much for static electrical discharge caused by wind and small charged particles in the air. I've seen first hand how long ungrounded wires (like a fence...or an antenna in this case) can develop some pretty significant static electrical charges (enough to shock the bejeezus out of a fella if he's not careful). This is the charge I'm trying to dissipate or anticipate.




edit on 10/1/2017 by Flyingclaydisk because: (no reason given)



posted on Oct, 1 2017 @ 07:37 AM
link   
The reason for asking the grounding question is two-fold...

1. Seems to me that if I ground the radio chasis to the same ground the antenna is grounded to then I've completely defeated the lightning protection by effectively jumpering it out.

2. Different grounding question; I've read that the antenna should be grounded with a ground exactly 1/4 of the wavelength of the antenna (to make it 'invisible' to the RX). I haven't really done this. My ground cable is however long the ground path is for the house (because it's connected to the house ground). Is this really that big of a deal. Not sure I want to go out and start driving separate ground rods all over the place.



posted on Oct, 1 2017 @ 07:48 AM
link   
a reply to: Flyingclaydisk

So are you using the 20ft of coax as the actual antenna? You may want to run a bare-wire antenna that connects to your coax 'feed' in the center. The longer the wire the better it will perform on the lower end of the SW bands. Since you're not transmitting, impedance matching is less of a concern. For best performance you'd use multiple long-wires of different lengths optimized for the bands you're interested in. The same antenna can be designed using multiple long-wires and connected at the end.

Here's a better description: SW antennas



posted on Oct, 1 2017 @ 07:55 AM
link   
a reply to: blackcrowe


You could add an external pre amp. They do drag in a bit better.


This radio actually has two different on-board pre-amps. It's a pretty nice radio.



posted on Oct, 1 2017 @ 08:02 AM
link   
a reply to: Flyingclaydisk

No worries.
I can't help anymore.
Hope you get it sorted.



posted on Oct, 1 2017 @ 08:08 AM
link   
a reply to: jtma508

No, the coax is not the antenna. The antenna is a 45 foot long end-fed HF antenna. It is effectively a bare wire antenna (it has insulation on it, but other than that). It's a packaged antenna so it was (in theory) already set up correctly.



posted on Oct, 1 2017 @ 08:25 AM
link   
I'm getting DX out of New Mexico and the Pacific NW right now on 80m. A little bit of Hawaii, but it's pretty faint.

3.796mHz



posted on Oct, 1 2017 @ 08:26 AM
link   
a reply to: Flyingclaydisk


Seems to me that if I ground the radio chasis to the same ground the antenna is grounded to then...

One must remember that a DC ground is not the same thing as a RF ground. Even gnd conductor(s) must be viewed as a transmission line in RF land.



posted on Oct, 1 2017 @ 08:34 AM
link   
a reply to: Flyingclaydisk

That being the case you should be good to go. The length of the HF element will determine where your reception 'sweet-spot' is. The pre-amp suggestion is bogus. It will raise your noise floor. You have a nice radio and should be able to get pretty much anything. Placement of the antenna is key. I have a 'mystery antenna' on my Yaesu FT897D and have been able to talk to people all over the world. No ore than a wire antenna like yours and mounted about 20ft up in the trees, so not ideal.



posted on Oct, 1 2017 @ 09:20 AM
link   

originally posted by: Cofactor
a reply to: Flyingclaydisk


Seems to me that if I ground the radio chasis to the same ground the antenna is grounded to then...

One must remember that a DC ground is not the same thing as a RF ground. Even gnd conductor(s) must be viewed as a transmission line in RF land.


Hence my 2nd point about the 1/4 wavelength issue.



posted on Oct, 1 2017 @ 10:16 AM
link   
a reply to: Flyingclaydisk

'mornin' FCD...just a simple suggestion based on your home's elevation footage above sea-level....perhaps a second antenna relay in a different location and elevation on your property to compliment, bigger or of different style?

Add signal amplifier to one...or both...or in between the two to base



posted on Oct, 1 2017 @ 11:30 AM
link   
a reply to: Flyingclaydisk

I was a real HAM enthusiast, back when in the service. There is so much great info out on the web on how to setup a decent system, it is rather overwhelming. What is great about SWR's is that they can communicate world-wide if properly configured, and when disasters strike regions of the world, usually it is amateur radio enthusiasts who are able to get first contact with each other. This would be especially useful today, with all of the Caribbean islands that are still out of touch using conventional comm. The serious have SWR setups and generators to run them, because it is required in emergencies.

Art Bell, who is and expert in SWR, has some great video's and blogs out there which are easy to find. Recently, he had build a full wave loop antennae, which he claims is the most powerful he has ever used. Great read in the eHAM blog:
Art Bells full wave loop SWR antennae

Good luck with your setup, I am sure it will consume many hours of excellent conversation and entertainment.



posted on Oct, 1 2017 @ 05:51 PM
link   
I would put the matching device first from the radio, after the long coax or the lightening surge protector comes off the antenna.

The antenna length will be a compromise with the long wave frequencies. 3.796mHz would have a 259 foot long full wave antenna. Your antenna would probably work best for around 22MHZ

Freq Wavelength Calculator

The ground wire should be a certain gauge (don't remember what) solid core wire that attaches to an iron bar buried 3 feet (I think) into the ground (the actual dirt ground). Don't actually ground any elements, just the surge protector or the mast or whatever the antenna is attached to.

ETA: A BALUN is important. The coax is an unbalanced line and without a balun, the coax shielding acts as a radiating element and can damage the radio or even electrocute you when transmitting.
edit on 1-10-2017 by MichiganSwampBuck because: added extra comments

edit on 1-10-2017 by MichiganSwampBuck because: typo



new topics

top topics



 
5
<<   2 >>

log in

join