External Antenna for ICOM IC-r75

[XPS720]

I have an all band vertical antenna in a range of 500 khz to 2000 mhz and it works great with scanners and my "AOR 8600 Mark 2". I also use this antenna on the RTL-SDR Dongle and the HF is great. Now if I put the PL-259 on my ICOM ICR-75 the antenna is not giving this receiver a strong signal. Even a local AM station is weak. Help me to get this great receiver on my new external antenna.

Thank you,

 

[ka3jjz]

Comparing HF performance of an antenna using a wideband receiver and cheap dongle SDR is always an iffy proposition, but....

Let's take the obvious stuff first - RF Gain all the way to the right, correct antenna port selected (there are 2 - one is a 500 ohm terminal, the other, as you noted, is a PL359 connection). Precisely what vertical are you using?

I see the squelch and RF Gain seem to share the same control. Make sure the control for RF Gain is active, not the squelch. Using Squelch on HF is not really a good idea...

Mike

 

[ka3jjz]

If this is a random wire or inverted L that is not using coax, put the lead in on the 500 ohm terminal....Mike

 

[MisterLongwire]

Don't know if one can consider the AOR to be...well...<sic>

 

[majoco]

I'd like an all band antenna 500kHz to 2GHz - but I s'pose any bit of wire fits that requirement - it just depends on how well....

 

[ka3jjz]

Very true. No antenna that is that broadbanded is ever going to have the same frequency response across its entire range. Not happening. That's why I wanted to know precisely what antenna the OP is using.

Mike

 

[XPS720]

The antenna has an 8 foot vertical for HF and next to it a VHF to UUHF - 2 separate antennas on 1 mount.

 

[Ubbe]

It's the AOR SA7000

SA7000 | ANTENNAS | AOR,LTD. Authority On Radio Communications

AOR SA7000 Super wide band base aerial system - AOR Ltd

AOR SA7000 - 30kHz-2000MHz, Receive only, Wideband whip antenna The aerial is designed for areas where space is a problem or when an "unobtrusive" installation is essential. The SA7000 is a passive arrangement providing two whip elements: a long element for short wave up to 30 MHz and a second...

radioaficion.com

AOR SA7000 Wideband base station antenna

I only found one Eham review on this antenna which was positive, I read a few threads here stipulating that any antenna system receiving above 500 MHz utilizing a SO239/PL259 combination will be deficient due to certain characteristics of the connectors design parameters. Can anybody confirm or...

forums.radioreference.com

/Ubbe

 

[ka3jjz]

Likely you are right, Ubbe...

 

[XPS720]

FYI I did purchased the SA7000 and I like it for my 3 scanners but my IC-R75 doesn't like it. I wonder If I must try just the outside line of the cable or just the center wire on the 300 ohm connector? If it is a possibility I will cut a PL259 connector off and replace the wire.

 

[ka3jjz]

If the suggestions I gave didn't help, then your next step is to try to feed the antenna differently. How is this antenna being fed? What is this 300 ohm connector? You might try to connect to the 500 ohm terminal directly instead just as an experiment - just short the 2 ends of the 300 ohm cable together with a clip lead and feed it that way.

It will not damage the radio in any way, and you might learn something.....Mike

 

[Ubbe]

What antenna did you use prior to this one and did that work as expected?

The R75 has attenuators and pre-amps and a gain control. Set attenuator off and pre-amp to on and turn the gain up. Remember to have AGC on or you will only hear a distorded audio and of course the correct mode, AM for broadcast stations, and filter to wide.

Maybe the R75 are faulty?

/Ubbe

 

[ka3jjz]

I see that this antenna comes with 15 foot of coax with a BNC connector, which will not mate properly with a SO239. I would substitute this cable for one that has a BNC connector for connecting to the duplexer, and a PL-259 for the Icom. Yes that will be a bit lossy at freqs higher than 450 Mhz, but the loss at HF is negligible.

There is no 300 ohm section unless the feedline was changed out....Mike

 

[XPS720]

Great news I found the problem with the IC-R75. I swamped the cable on the RTL-SDR, very small cable, and my rig sounds great now. Now explain that one to me. To get a stronger signal I need to put it on preamp 2 but it sounds great now. I thank all that responded to my problem.

73's

 

[Ubbe]

It's a short vertical for HF that gives a very weak signal so you have to amplify a lot.

I had a 25ft wire to my R75 and almost had to use the attenuator setting but using a 3ft loop, which gives much lower signals, I had to use the pre-amps. But the end result of signal noise ratio where pretty much the same, both antennas received equally good in the upper part of HF.

SMA connectors tend to unscrew themselfes if not tighten enough, use only finger strenght, no tools.

/Ubbe

 

[XPS720]

It's a short vertical for HF that gives a very weak signal so you have to amplify a lot.

I had a 25ft wire to my R75 and almost had to use the attenuator setting but using a 3ft loop, which gives much lower signals, I had to use the pre-amps. But the end result of signal noise ratio where pretty much the same, both antennas received equally good in the upper part of HF.

SMA connectors tend to unscrew themselfes if not tighten enough, use only finger strenght, no tools.

/Ubbe

It's a short vertical for HF that gives a very weak signal so you have to amplify a lot.

I had a 25ft wire to my R75 and almost had to use the attenuator setting but using a 3ft loop, which gives much lower signals, I had to use the pre-amps. But the end result of signal noise ratio where pretty much the same, both antennas received equally good in the upper part of HF.

SMA connectors tend to unscrew themselfes if not tighten enough, use only finger strenght, no tools.

/Ubbe

Yes it sounds great even with preamp 2.

 

[ka3jjz]

As the old saying goes, you want better performance from your HF radio, a better antenna is needed. What is your situation regarding putting antennas outside (always best)? I assume you got the vertical because your space is limited. Loops are a great option if this is the case, and we have a very good wiki on the subject here....

Loops - The RadioReference Wiki

wiki.radioreference.com

Mike

 

[MisterLongwire]

Why is it a person buys a decent radio and is reluctant to get a "decent" antenna along with it? There is not 1 antenna that is a do-it-all. Not one!
If all else fails get a PAR SWL end fed antenna. The wire antenna works great and does not have to be in a perfect line. Only 40 feet long. As for the AOR antenna, I am sorry you spent your hard earned $ on that. But we all learn. If all else fails go to library or even a ham shack and pick up ARRL books on antennas.

 

[XPS720]

As the old saying goes, you want better performance from your HF radio, a better antenna is needed. What is your situation regarding putting antennas outside (always best)? I assume you got the vertical because your space is limited. Loops are a great option if this is the case, and we have a very good wiki on the subject here....

Loops - The RadioReference Wiki

wiki.radioreference.com

Mike

Hello KA3JJZ
Yes antennas outside are great, I am one to know now. My ICOM 75 works great. Now I have a question to you as a Ham Operator. I love Ham Radio Deluxe on my ICOM receiver. I now see an update was done since my last use. Only problem is now it requires a Ham licence. I have learning problems at 66 and will never see a personal call sign. I love to DX all over the world and 80 Meters is my #1 band. Now going back on HRD. I am not sure if it is the best to use on receive and transmit but can I get it without a Ham licence.

73's and hope to hear your call's on 80

 

[ka3jjz]

I really don't know - I don't use HRD as it's too ham oriented. I like to see other modes, many of which we can't use (yet).

Do you use HRD strictly for radio control, or are there other things you do as well? HRD has so many functions that it's likely no one software package will cover everything HRD does.

There are MANY programs out there for the 75, but probably none as comprehensive...Mike