Small plastic roof mounted car antennas: why?

[radioman148]

I've got the standard factory radio with whip antenna in my 1999 Ford Ranger.

Good for you--that's a real plus.

 

[radioman148]

I know of someone who, using a 2006 Ford Ranger's radio and whip antenna, heard 8.5kW 650 KGAB from Orchard Valley, WY (near Cheyenne) until he crossed the Mississippi River in St. Louis, 792 miles away. Also, using the same radio, he heard 50kW 640 KFI Los Angeles to just east of Willcox, AZ (50 miles W of the AZ/NM border, 506 miles from KFI) and 50kW 700 KALL North Salt Lake City, UT, into the western part of New Mexico, probably over 617 miles away. He also heard 250-watt non-dir 690 KWRP Pueblo, CO, 193 miles away about 40 miles into Kansas on I-70.

Would the car radios from the 1960s, for example, be much better at midday AM DX than that?
For example, using a portable radio and tuned loop antenna, I've been able to hear 50kW 680 KNBR San Francisco, CA (445 miles), and 50kW 700 KALL North Salt Lake City, UT (626 miles), at my house, in spite of being only 32 miles from 77 kW 690 XEWW Tijuana, Baja Calif Norte. With a reasonably selective and sensitive car radio and antenna, should I expect a better signal from KALL with less splatter from XEWW?

Can't say whether the car radios from the 60s would be better than what you described, but one thing for sure there was less noise around then.

 

[cyberdad]

Let me put it this way....  When I snagged WLS on the north shore of Oahu in February 1965, it was on a 1962 Chevy Impala car radio.

To make a broad-brush statement, the 60s car radio had good to very good sensitivity and fair sensitivity.  Of course there were exceptions. 

The GM/Delco radios may have been the best, but Ford was right up there with them.  We had a '66 Ford Galaxie 500 with a factory radio that was fabulous for DX. Chrysler radios were also pretty good, but my memory is they were a bit more "finicky" and malfuction-prone.  As it was, with all of them, you had to make sure that your electrical system was in good working order.  A worn distributor cap or deteriorating sparkplug wires (or sometimes even sparkplugs themselves) invited noise that would negate any DX.

One issue was that some GM models had an antenna trimmer pot that you could adjust with a small screwdriver, IIRC.  On the '62 Impala, you located it by removing the tuning knob (or maybe the on/off-volume knob. I forget).  Problem was, the trimmer had a tendency to eventually drift out of adjustment for no apparent reason.  Most people had no idea that the pot even existed...let alone how to adjust it.  The result was you had a lousy-performing radio instead of a good one!

That was the case originally with my Mom's '62 Impala, as well as at the end of the decade with my college roommate's nearly identical model. 

He was from Boston.  I removed the knob, and provided him with "Instant WBZ"....in Iowa! As a token of gratitude, he allowed me the occasional private use of the Chevy's back seat!

 

[radioman148]

Let me put it this way.... When I snagged WLS on the north shore of Oahu in February 1965, it was on a 1962 Chevy Impala car radio.

To make a broad-brush statement, the 60s car radio had good to very good sensitivity and fair sensitivity. Of course there were exceptions.

The GM/Delco radios may have been the best, but Ford was right up there with them. We had a '66 Ford Galaxie 500 with a factory radio that was fabulous for DX. Chrysler radios were also pretty good, but my memory is they were a bit more "finicky" and malfuction-prone. As it was, with all of them, you had to make sure that your electrical system was in good working order. A worn distributor cap or deteriorating sparkplug wires (or sometimes even sparkplugs themselves) invited noise that would negate any DX.

One issue was that some GM models had an antenna trimmer pot that you could adjust with a small screwdriver, IIRC. On the '62 Impala, you located it by removing the tuning knob (or maybe the on/off-volume knob. I forget). Problem was, the trimmer had a tendency to eventually drift out of adjustment for no apparent reason. Most people had no idea that the pot even existed...let alone how to adjust it. The result was you had a lousy-performing radio instead of a good one!

That was the case originally with my Mom's '62 Impala, as well as at the end of the decade with my college roommate's nearly identical model.

He was from Boston. I removed the knob, and provided him with "Instant WBZ"....in Iowa! As a token of gratitude, he allowed me the occasional private use of the Chevy's back seat!

I didn't know you could get good DX from the back seat ;D

 

[FreddyE1977]

What happened to a standard metal (encased in a plastic sheath) "whip" antenna, or even the rear window mounted ones?

short answer, car washes do not like them

 

[crainbebo]

I have used the following car radios:

1996 Chevy Suburban (current one). Very good FM almost equal to a Grundig G5 except for some sensitivity issues on first-adjacent channels. AM is also good, little engine noise. I have heard stuff 200+ mi out in the late afternoon on AM on this thing.

1988 Buick Regal: Good FM (heard 150 mi at 2100+ feet, this was actually at the Indian John Hill rest area near Cle Elum, WA, but the 150+ mi might just be knife-edge from elevation), terrible AM even with whip. Engine noise fest!

1988 Chevy Celebrity: Poor-fair FM and poor AM.

2010 Toyota Corolla: Used as a rental car for a Yakima trip. Excellent AM and the best of the best for FM. Best sensitivity I've ever heard to first-adjacents, with this in Yakima heard KBLD 91.7 Kennewick when local (very splattery) KDNA 91.9 was ON AIR! Also have heard 100-150 mi in all directions at 2500 ft above Ellensburg, WA on this thing, even KNCW 92.7 Omak, 4100w @ 114 mi, which my G5 didn't get. Returning the car back to Hertz, heard KMNT 104.3 Centralia rock-solid in Bothell even with KMCQ's splatter, and KPQ 102.1 quite well. Have also heard KDBL 92.9 Yakima fighting with KISM 92.9 Bellingham out in Easton on this thing. Amazing. For AM, Vancouver, BC stations came in quite well, even with the in-glass antenna. CHMB 1320 was in nicely in Kirkland.

Early 2000s Chevy Spartan body van: Used this one for storage moving. FM is very good, KPQ 102.1's 35kw at 2654 feet HAAT is rock solid into Bothell. AM is average, but zero engine noise was heard!

-crainbebo

 

[Tom Wells]

One ISSUE was that some GM models had an antenna trimmer pot that you could adjust with a small screwdriver, IIRC. On the '62 Impala, you located it by removing the tuning knob (or maybe the on/off-volume knob. I forget). Problem was, the trimmer had a tendency to eventually drift out of adjustment for no apparent reason. Most people had no idea that the pot even existed...let alone how to adjust it. The result was you had a lousy-performing radio instead of a good one!

That was the case originally with my Mom's '62 Impala, as well as at the end of the decade with my college roommate's nearly identical model.

He was from Boston. I removed the knob, and provided him with "Instant WBZ"....in Iowa! As a token of gratitude, he allowed me the occasional private use of the Chevy's back seat!

It was behind the outer ring on the tuning knob on many models.

It's not an issue....it's the very part that permits a perfect impedance match between the radio and whip for best AM sensitivity.
Some had them behind the tuning knob ring, and some had them somewhere on the back of the case.
It is a trimmer capacitor, and there is nothing to lock the screw in place except the friction of the screw against the springing
built into the compression-type adjustable cap. So they DO need touching up once a year or so.

Modern radios with no such adjustable trimmer for AM shouldn't be expected to do well on AM except by happy accident.
Last week I had go out from work and jump start a co-worker's car 3 blocks away.
It was a 2003 Honda, and some aftermarket radio with a whip on the rear fender.
While we were waiting I had him put on some AM, and was shocked to hear full satisfying sensitivity on graveyard channels.
So it can happen, I'm just a stinker about liking the continuous tuning of old radios.

 

[trusty]

I'm just a stinker about liking the continuous tuning of old radios.

I had a VW beetle with an AM radio when I was in college in the Tampa/St. Pete area when the top station was WLCY/1380. I had large speaker that perfectly fit into the top of a small beer keg which I installed behind the rear seat - GREAT sound! Would rival any digital bass you can feel coming down the road today.

WLCY was heavy on bass - so much that it sounded like it was in the mud in my car - except when I manually tuned it to somewhere around 1382 when the highs kicked in and the bass didn't overpower them. I tell you, it was better than FM - the AM top-40 sound with heavy bass and crystal clear highs - even the evening noise from other stations (when LCY cut power) sounded good.

 

[cyberdad]

In college (late '60s), I had a friend from the Tampa Bay area. He had a good radio/cassette unit and a stack of cassette recordings of WLCY. To this day, I still remember how impressed I was with their audio. (Apologies for the veer OT).