AOR AR-DV1 - Antenna ??

[hth999]

I just received my AR-DV1 yesterday. Not too pleased. The radio is attractive and well built, but it has no front end at all. My Wellbrook Loop for HF completely destroys or overloads the radio. I have never seen such a poor front end for a 1200 dollar radio. ( I do have some strong local AM stations, which is probably why, but the radio cost's 1200.00 dollars, cmon, AOR !)

I do have a Discone antenna ( nothing special ) mounted in my attic.108-1300 mhz. This also overloads the radio. The local FM stations bleed into the AIR band, rendering it almost useless. What is this?

I have found the best performance or balance is from a simple whip antenna. But I did not buy a portable radio, to be used by a whip antenna. Does anyone have any suggestions regarding an antenna in a strong signal area? not necessarily for HF, but for VHF and UHF. I didn't buy the radio for HF, that's a bonus.

Also, I have many P25 transmissions in my county. They are strong. My scanners pick them up very well. They are trunked. I know this radio cannot pick up trunked transmissions, but I thought you could put the radio on one of the signals ( 851.2 ) or sites, and it would pick up the signal. It would be a one way conversation, but you would hear a dispatcher. Any thought's? I have followed the manual, but maybe I missed something. Thanks, HTH

 

[marlbrook]

Some thoughts

I have not experienced this at all with my AR-DV1.

That maybe because there are not enough strong signals to cause interference here perhaps.

Assuming you have not got a 'rogue/faulty' receiver, have you tried adjusting the many bandwidth options available, on VHF/UHF?

I actually have a pre-amp in line, with my discone, and have not experienced any overloading even then.

Like you, I view SW/HF on the receiver as a nice little bonus, but never expected to try it for serious use on those bands. The same still applies though, re. bandwidth options. In fact on my long wire, I am very impressed with the AR-DV1's HF performance.

You will no doubt have considered this, but if the AR-DV1 is not faulty, the only other option is to either incorporate an attenuator between the receiver and the antenna, a bandpass filter to eliminate the broadcast FM interference, and/or a pre-selector on HF.

This may seem 'daft, but as a temporary measure try putting a very small value capacitor between the aerial and chassis. I realise that will attenuate the signals a little, but hopefully not enough to lose any completely.

Also try earthing the AR-DV1,chassis, in case those strong FM Band signals are finding another way in, directly to one of the circuits, on top of the aerial path, and by-passing the filters.

Some ferrite rings on the power cable too, for the same reasons.

What you are finding now would be intolerable in an expensive receiver, but hopefully you will get enough replies here to point to whether this is peculiar to your AR-DV1.

I cannot comment on the P25 questions you mentioned. It is not used over here.

Please keep us informed

Cheers, Jeff

 

[hth999]

I think my radio is fine. I have a FM transmitter about 3 miles from the house. 2 stations use it. 98.7 and 92.5. Both are +60 on the S meter on other radio's. I do have a FM trap made by Par. I tried using it, but it seems to de sensitize the radio, including the airband which I don't understand. The bleed thru on the airband is what concerns me. You can actually here 98.7 music in about 5 different frequencies, like 118.8, 133.825, and others.
I have an Icom R-8500, that is bullet proof, and an AOR 5000, that works well. But I got this new receiver for the digital modes. Likely it won't work in my area, because of extremely strong signals.
Anybody else experiencing problems located in strong signal area's? HTH

 

[marlbrook]

Additions

I edited my message a minute ago, with some extra suggestions

Cheers

 

[EricCottrell]

Hello,

I use a Wellbrook ALA1530 antenna and have AM stations within a couple of miles. The Wellbrook output is hot to begin with on Medium Wave. I have to use a MW Band-Reject filter for the AOR AR-DV1 below 18 MHz and some other radios. The only ones that do no suffer at all are my commercial HF receivers.

I have not found any problems with FM, but I usually have a passive splitter in-line.

73 Eric

 

[hth999]

Thanks for your suggestions. I think I solved the problem. Since I was experiencing overload issues with the FM BCB, I decided to try an in-line attenuator. I forgot I had them, but I have 6, 10, and 20db attenuators. These are bnc, so they work perfectly. I went to 134.500, and heard the bleed thru of 98.7 playing rock music. At 134.5 I should hear the St Petersburg Tower, with weather and airport updates.I inserted the 6bd attenuator, viola! the bleed thru was gone and there was the St Petersburg Tower signal! It's not strong, maybe a S-5, but it is readable and strong enough to listen to. I then went to 133.825, which is McDill AFB. It's an automated message giving pilots messages about runways, etc. It is a little weaker, but also readable. I couldn't believe it! Just 6 db of attenuation! I went up and down the Airband, there is some bleed thru, but it is workable and not bad at all. I feel much better now. I was going to try to return it, but not now. Even the FM BCB is better, and even the AM BCB is not bad using my discone antenna. It picks up all the local AM stations, which is just what I want. If anyone is experiencing the overload problems of a strong signal area, you may need to attenuate the signal a bit. it seems the " Built In attenuator" on the AR DV1 doesn't work very well, or not at all. I'm not sure how it is supposed to work. HTH

 

[NL12892]

i have not problems wiht strong signals in the air band we have a strong radio signal on 104.100 mhz 10 Kw power no problems .

 

[hth999]

Thanks for your response. I have definitely isolated the problem with regard to strong signals. I have a FM transmitter, according to radio-locator.com, it's less than 2 miles from my home. It is a 50,000 watt transmitter for both 92.5, and 98.7. Both are +60 using my discone antenna.( 108-1300 mhz ) If I were say 10-15 miles away, I don't think this is an issue. I just happen to be too close to that tower. Bottom line, I was able to put a 6bd in line attenuator on the coax feed and it has worked well. I'm surprised 6 db has worked, but glad it did. I still have some bleed thru of 98.7 in several frequencies ( Airband ), but most are workable .HTH

 

[AA6IO]

My AR-DV1 is useless in Los Angeles area with my R8 vertical (Cushcraft:40-6 meter) antenna or my Pixel loop. Overloads like crazy. Can't hear much of anything up to 25 Mhz. I have KFI 50,000 watt 640 Mhz with antenna 2 miles away. But with a simple MFJ tuner (MFJ-956), seems to work quite well.
Only receivers I have that don't overload are my Perseus SDR and ICOM ham rigs. I agree. I would have expected a much better front end on a $1200 receiver. But it is what it is. Now with Uniden/Whistler having DMR available, don't think I would have bought AR-DV1. But that is all in hindsight.
I know some love the AR-DV1. I find it mediocre at best compared to dedicated receivers for each band/mode. But not bad for an all--in-one solution. Don't use it much at all. Uniden scanners and Perseus/Elad get much more air time here at my QTH.