Gary Reports Weak AM Performance on His Sangean LB-100

While I'm getting strong AM on my Sangean LB-100, Gary reports otherwise (environmental factors at work here?):

I finally bought a Sangean LB-100. I'm surprised at just how weak the AM reception is. Even the strongest local stations that I regularly listen to -- KFI and KNX -- have an excessive amount of hiss. My CCRadio-SW and Sangean WR-2 get far better reception. Even my little Tecsun PL-380 has better AM sensitivity. The LB-100 doesn't seem to be any more sensitive than my little Sangean DT-400W, which is pretty amazing considering the size difference between the two. The LB-100 has about a 3" ferrite bar, but the one in the DT-400W is much shorter.

When using the LB-100 with my Black Box tunable, passive loop -- a rectangular loop similar in performance to the Terk loop -- the AM is much better, and totally hiss free on the stronger stations. I hadn't intended on using the LB-100 with a passive loop, as this reduces the convenience quite a bit, since you have to move the loop around with the radio, and re-tune the loop for each station.

I find that the LB-100 has a little too much upper bass for talk radio, but it's acceptable. I probably wouldn't be happy with the U3's sound quality on talk radio. I apparently prefer less bass on AM than Jeff does. This is one reason why radios with significant bass response should have a bass control instead of just a tone (treble) control. Of course, the LB-100 has neither.

On the plus side, the FM sensitivity of the LB-100 seems quite good, even with the little rubber duck antenna. And the sound with FM music is very pleasing.

I'm not sure if the AM performance of my LB-100 is typical or not. I'll have to decide whether to keep it or return it. This is pretty disappointing.

Comments

[Ed S.]

When I borrowed Jeff's, in my house I noticed background hiss on strong stations like KFI, too. Of course, I don't think this radio was meant for near-field (close-up) listening...more likely to be used outdoors where such noise would be masked. I also thought it a bit boomy for talk radio. Again, inside a house is probably not the environment this radio was designed for. Outdoors, it should fare better.

[Gary]

Jeff - I don't think this is an environmental issue, because my other radios are used in the same environment.

This evening I did some more comparisons. On some frequencies, my tiny DT-400W is actually more sensitive than the LB-100. I also found that my PR-D7 is far more sensitive than the LB-100. The PR-D7 is a decent radio, but it's not that sensitive on AM. When I bought it, I was hoping that the LB-100 would be at least as good as my PR-D7.

[Jeffrey McMahon]

Gary, I wonder if it's defective. Perhaps a broken ferrite? Or perhaps it is the nature of the beast. Yet mine works fine where I live, not as good as the Sangean U3, but very good. Weird.

[Gary]

Jeff - It crossed my mind that my LB-100 may be defective. I sent a message to Sangean indicating the relative performance of my LB-100, DT-400W and PR-D7. If they think it's defective, I'll ask Amazon for a replacement. If they think it's performing normally, I'll ask Amazon for a refund.

I can't believe they would have designed the LB-100 to be far less sensitive than the PR-D7 on AM. Perhaps someone else who reads this blog has both an LB-100 and a PR-D7, and can do a comparison on some weak daytime signals. My PR-D7 can pick up clearly intelligible stations that are nothing but weak mumbling on my LB-100. On the stronger stations, the LB-100 has lots of hiss, but the PR-D7 is relatively hiss free.

[Jeffrey McMahon]

I had a PR-D7 whose AM sound was pretty bad and I sold it. I prefer my LB-100's AM. Quality control could be an issue here. For great AM, I'm licking my chops at getting a Sangean Fatbox for under $200. Haven't seen one at that price for a while though.

[Huesby]

Excuse me but what kind of sensitivity you expect with so short ferrite ? Didn't you know that the longer the ferrite the more sensitivity ?

[Trafind Com]

very nice the item. i like it

[Gary]

Hugo - As far as I know, the ferrite bars in the PR-D7 and LB-100 are about the same length, but my PR-D7 is far more sensitive on AM than my LB-100. Also, the ferrite bar in the LB-100 is at least 50% longer than the one in the DT-400W, but the sensitivity of my LB-100 is actually inferior to that of my DT-400W.

[Huesby]

Gary:
Do you know that radio factory workers position the coil in a predetermined position (more or less X inches from the edge) instead of actually putting the coil in the optimun position for peak performance ? They try to save time doing this.....and time is Money...

[Gary]

I got a reply back from someone at Sangean regarding the lack of AM sensitivity on my LB-100. According to him, the LB-100 is actually less sensitive than the pocket-sized DT-400W. He went on to say that it is derived from the European Lunchbox radio, and AM is not that important in Europe. He says they will try to improve the sensitivity of the LB-100 in the future.

Basically, it sounds like the low AM sensitivity of my LB-100 is due to the design and not a sample defect. Too bad.

[Jeffrey McMahon]

I'm not convinced by the Sangean rep's explanation. I've got two Lunchboxes, one at home and one in a high-interference work office and both grab AM stations with ease and no background noise.

[Gary]

Jeff - At this point, I'm not sure what to think.

I can always exchange my LB-100 for another one with Amazon, but if the replacement has the same poor AM sensitivity then I might be stuck with it.

[Gary]

I realize now that the difference in our assessments of the LB-100 is probably just that most LA stations are much stronger in Torrance than they are in Simi Valley.

Here's a comparison of the field strength of some of the stations I listen to (columns are Call Sign, Frequency, Torrance Field Strength, Simi Valley Field Strength)

KNX 1070: 585, 10
KFI 640: 75, 13
KRLA 870: 37, 19
KSPN 710: 37, 33
KABC 790: 26, 7
KLAC 570: 18, 6
KFWB 980: 16, 2

In every case except KSPN, the field strength in Torrance is much higher than in Simi Valley. KNX is almost 60 times as high (you must live almost on top of the KNX transmitter).

The data above was gathered from this web site:

http://www.v-soft.com/ZipSignal/

[Jeffrey McMahon]

I suspect that our different location does indeed make a huge difference in AM reception. I wonder if you'll need to get an Internet radio, something that hasn't appealed to me yet.

[Gary]

Actually I have a SqueezeBox Boom, which I use in my bedroom. I wouldn't want to use it for a garage radio, which is what I bought the LB-100 for.

I have a CCRadio-SW in the bathroom (which has worse reception than the other rooms in my house) and it gets good AM reception on most of the stations I listen to regularly, and its FM reception is outstanding.