Increase AM Reception in Automobile for HD Evaluation

[flintstone mop]

Hello All
I am posting in QSO coz this is far out from Ham radio BUT is related to the MF band and AM radio.
I purchased a Pioneer super duper AM/FM and bought the optional HD receiver. Which is also AM/FM.
I jumped the gun and am evaluating the HD tuner. The head unit disregards the built-in tuner if it see the outboard HD tuner... Through some IP plug.
Vehicle has the world famous in-glass (rear window) AM/FM antenna. It also has a 'pre-amp!!" in the headliner. Without power from the head unit the FM reception is spotty and AM is ok locally.
With 12vdc the FM comes to life and no dead spots. AM reception is improved when the preamp is powered BUT still not enough amplification for the AM b'cast mode. The head unit acts like there's a noise gate or "squelch". And the menus do not address letting me adjust to hear everything. Static,  weak stations, etc. What could I do to increase AM reception without drilling holes in the vehicle and the good old fashioned 36 inch whip?
I'm thinking along the lines of C.Crane. They like to use inductively coupled devices to improve AM reception for a portable radio. These little gidgets do work.........How could I incorporate the same type of design in a mobile environment??

The Japanese/Chinese are still not able to make a good auto car radio to grab the AM stations, I am not impressed with the HD AM radio function. Delco was about the only good car radio. Even under a bridge the AM never faded.
Anyway the HD FM is impressive!!! subject to the terrestrial shortcomings. But mostly pretty neat stuff. The audio is better than analog FM. A lot more stereo and a cleaner audio. Some stations have two HD channels and usually play very nice music with little or no interruptions. ALMOST like satellite radio. Except for the terrestrial fading. The radio nicely goes to the analog channel and it is hardly noticeable on the main channel. The HD 2 channel just drops out and comes back as the signal returns and the buffer reloads.
I imagine in a big (market) with many offerings that HD radio is a good thing.
I was wanting to experience the AM though. That would require a superior AM radio with something beyond an invisible antenna.

Any ideas guys or gals?
Fred

[KA0HCP]

I have a 2001 Buick and found that my FM and especially AM reception improved significantly when I bonded the hood, trunk and doors for my HF radio installation.

I added static wicks at the rear of the car a couple years ago and it decreased static build up in damp and rainy conditions.

Good luck!

p.s.  http://www.k0bg.com   Alan has an outstanding site on mobile installs.

[flintstone mop]

I'll check that out! Thanks. I overlooked the fact that it could be auto noise masking the real radio signal. Another can of worms.

Fred

[KM1H]

I like to listen to 1540 AM when driving locally but Im at its 250W fringe area. The cure was to insert a base loading coil in the antenna and tweak the radios antenna trimmer. By ear the improvement sounds like 20db which is just a wildass guess but the signal is now well above the noise unless I have the blower on high or the wipers on.

FM seems unaffected but I rarely find anything there worth listening to.

[k4kyv]

FM seems unaffected but I rarely find anything there worth listening to.

And you find anything in the AM band worth listening to?

About the only broadcast stations I ever listen to any more are the NPR and non-commercial University stations, and the ones here are all in the FM band except for one 10KW NPR station in Nashville on 1430, but @ 50 miles away, noise from the power lines that run alongside the road pretty much wipe it out. At night they reduce power and don't even quite make it to the Nashville city limits.

[flintstone mop]

I like to listen to 1540 AM when driving locally but Im at its 250W fringe area. The cure was to insert a base loading coil in the antenna and tweak the radios antenna trimmer. By ear the improvement sounds like 20db which is just a wildass guess but the signal is now well above the noise unless I have the blower on high or the wipers on.

FM seems unaffected but I rarely find anything there worth listening to.

Yup those were the good days when we could adjust the little trimmer guy. This new stuff is ballpark electronics. AM is in the bottom of the pile.
Fred

[WA3VJB]

I see a "Service Support" contact field on the Pioneer website.  Maybe you should start a dialogue with them about undocumented button-sequencing that could open up the squelch or noise gate for AM band reception.

Also, is there still an external antenna jack of some kind?  Maybe J-S a long wire while you're in the driveway just to see how the radio behaves with a known good antenna. This would also facilitate testing for how much vehicle noise is generated when you start the car.

[KM1H]

Well Don, if National Palestinian Radio is all you prefer or can find down in hillbilly country I'll take pity on you.

AM is alive and well in this area.

Carl

[flintstone mop]

Further testing and riding reveal that this Gate Circuit or squelch is part of the HD tuner and cannot be defeated. But it does activate when the signal is really crappy. I'm not used to hearing a gated receive, if I'm trying to listen to an analog station.
I'm experimenting with an on-glass antenna that supposedly amplifies the AM AND FM signal with separate preamps. The GM stock in-glass antenna (rear window) also has a preamp in the headliner. No power to that Preamp and the FM is spotty and AM is only the local two stations in town when I am parked at my house. So, the tuner is really trying to grab the RF.

The terrain and distance from Greenville Pa and the Youngstown Ohio market is pretty rough. All it takes is about 7 mi closer to home and I am locking into the HD FM's from Youngstown Oh. In town with the buildings and low elevation of New Castle Pa. the FM's keep going to the  analog audio. I'm too far from Pittsburgh Pa. to get any activity from them. 50 mi and hilly terrain.
The ONE HD AM signal on 1390 is solid copy in HD all the way to my house after the initial 7 mi have been driven. WNIO 1390 used to play oldies and hits from the early late 60's. Now they talk about sports. But it sounds impressive.
The AM signal might be more tolerant to the terrain and not hit up too bad from multipath and sudden fading that happens in the FM band
Fred

[KM1H]

Hang a 53-4 Buick radio under the dash, a full size CB whip out back, and relax with great AM