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WBZ on 870?
- Thread starter aerie
- Start date
I get that all the time when I'm near Boston. It's some kind of spur signal. Someone here will give you the math formula.
Near RKO's sticks in Burlington you can hear 680 squishing 1360 (2 x 680)
Near RKO's sticks in Burlington you can hear 680 squishing 1360 (2 x 680)
Even many of the (otherwise) best systems today still have crappy, afterthought AM tuners in them.
aerie said:
...and of that $990, I would take a cash US money wager than its AM section cost less than one dollar in parts and labor.
Many of the very expensive radios are actually crappy tuners. 
The logic is that most people who paid serious $$$ for a sound system are not really radio listeners; they're more iPod or CD or DVD consumers. I think that logic is BS but that's what it is. :'(
FWIW, a good tactic with radios is to get an HD Radio tuner, if you can. Doesn't matter if you want to listen to HD or not, but the tuners in most HD Radio receivers are excellent tuners. They have to be to get the -20dBc (or -14dBc) HD carriers.
I'm guessing what Aerie is hearing is an intermod product of some kind, although I'm not sure exactly how. You can 850 on 1700 in a lot of Boston, actually. But that's just a simple harmonic, not an intermod product.
The logic is that most people who paid serious $$$ for a sound system are not really radio listeners; they're more iPod or CD or DVD consumers. I think that logic is BS but that's what it is. :'(FWIW, a good tactic with radios is to get an HD Radio tuner, if you can. Doesn't matter if you want to listen to HD or not, but the tuners in most HD Radio receivers are excellent tuners. They have to be to get the -20dBc (or -14dBc) HD carriers.
I'm guessing what Aerie is hearing is an intermod product of some kind, although I'm not sure exactly how. You can 850 on 1700 in a lot of Boston, actually. But that's just a simple harmonic, not an intermod product.
aaronread said:Many of the very expensive radios are actually crappy tuners.
FWIW, a good tactic with radios is to get an HD Radio tuner, if you can. Doesn't matter if you want to listen to HD or not, but the tuners in most HD Radio receivers are excellent tuners. They have to be to get the -20dBc (or -14dBc) HD carriers.
I'm guessing what Aerie is hearing is an intermod product of some kind, although I'm not sure exactly how. You can 850 on 1700 in a lot of Boston, actually. But that's just a simple harmonic, not an intermod product.
3rd-order intermod with WROL? (950 * 2) - 1030 = 870.
Is the presence of WROL making WBZ show up on 870? One thing's for sure, it's definitely WBZ
on 870...and I was getting the same result up in Beverly the other day.
on 870...and I was getting the same result up in Beverly the other day.
Yes, it's WROL. The second harmonic of 950 is 1900, and 1900 - 1030 is, you guessed it: 870.
The next question is: is that second harmonic of WROL really there? Or is it being generated in your radio due to front-end overloading?
When WCRB was on 102.5 and operating from the Cedar Street tower in Needham, its antenna used to pick up WODS at 103.3. That signal would get into the final stage of the WCRB transmitter, where it would mix with WCRB's second harmonic at 205.0 and produce a product a 101.7 that was a little more than 80 dB down. That was enough to be legal, but you could hear it on a car radio on Route 128, where WFNX would suddenly turn into WODS for a mile or so.
Perhaps something similar is happening between WBZ and WROL.
The next question is: is that second harmonic of WROL really there? Or is it being generated in your radio due to front-end overloading?
When WCRB was on 102.5 and operating from the Cedar Street tower in Needham, its antenna used to pick up WODS at 103.3. That signal would get into the final stage of the WCRB transmitter, where it would mix with WCRB's second harmonic at 205.0 and produce a product a 101.7 that was a little more than 80 dB down. That was enough to be legal, but you could hear it on a car radio on Route 128, where WFNX would suddenly turn into WODS for a mile or so.
Perhaps something similar is happening between WBZ and WROL.
Joined you folks on April 19th for the first time. Great writing and postings. (We have buddies in Boston whose wedding we attended).
* * * * * *
On certain radios, way out of sensible range from the Meadowlands tower farm in North Jersey, we'd get things like WINS 1010 plus WHN 1050 -- on 1090.
Or WNEW 1130 plus WLIB 1190 -- on 1250.
And here in NE PA, on a GE portable, close by the towers of both WPPA 1360 and WPAM 1450, I get a steady heavy-rock station underneath regional WLBR 1270.
It's WPAM, doing that multiple/sequence thing. It's odd that WPPA isn't there on '1270' at all -- just WPAM.
Perhaps that 870 WBZ spur, or image, is caused by another transmitter. The 950 one is a pretty far poke being heard in Beverly, though, I'd say
* * * * * *
On certain radios, way out of sensible range from the Meadowlands tower farm in North Jersey, we'd get things like WINS 1010 plus WHN 1050 -- on 1090.
Or WNEW 1130 plus WLIB 1190 -- on 1250.
And here in NE PA, on a GE portable, close by the towers of both WPPA 1360 and WPAM 1450, I get a steady heavy-rock station underneath regional WLBR 1270.
It's WPAM, doing that multiple/sequence thing. It's odd that WPPA isn't there on '1270' at all -- just WPAM.
Perhaps that 870 WBZ spur, or image, is caused by another transmitter. The 950 one is a pretty far poke being heard in Beverly, though, I'd say
Well I meant I was getting WBZ on 870 in
Beverly, not the 950 (WROL). I thought a previous
post alleged that somehow 950 was forcing
WBZ to show up on 870 somehow..
Beverly, not the 950 (WROL). I thought a previous
post alleged that somehow 950 was forcing
WBZ to show up on 870 somehow..
Thanks for the explanation, and it's interesting how one station can lead to _another_ popping up
on a certain freq. If, for example, WROL were to go silent, there would be no such problem...
on a certain freq. If, for example, WROL were to go silent, there would be no such problem...
Yeah, there's intermod products all over the place. I always have trouble remembering the math for some reason. But IIRC it's (local-signal x N) - (known-signal) = (new frequency where known-signal also shows up, but only in vicinity of local-signal). In theory "N" can be any harmonic, but in the AM and FM bands, it will almost always be "2", maybe "3".
In Winchester I don't hear this. I have a Superadio III and a good Grundig.
even "good" receivers get WBZ on 2060, 3090..and IP3 is usually good when it's like -40db? plenty of room for magic to occur, with the absurd powerlevels these broadcasters run to get over crappy radios and local interference. within a few miles of the blue hill, quite excellent radios have on 88.5 a mix of 89.7 and 90.9, glenn hauser calls these "leapfrogs"
Here in New Britain, CT, the overload frequency seems to be 94.9 FM. The commercial stations in the market are:
92.5 Waterbury/Hartford [West Peak in Meriden]
93.7 Hartford [West Peak]
95.7 Hartford/Meriden [West Peak]
96.5 Hartford [Avon Mountain in Avon]
100.5 New Britain/Hartford [Rattlesnake Mountain in Farmington]
102.9 Hartford [West Peak]
104.1 Waterbury/Hartford [West Peak]
105.9 Hartford [West Peak]
106.9 Hartford [Off of US 44 near Avon/West Hartford line]
The major AM stations here are:
840 New Britain [Willard Avenue in Newington]
910 New Britain [Radio Park in Farmington]
990 Southington [south end of Southington?]
1080 Hartford [Avon Mountain in Avon]
1120 Bristol/New Britain [?]
1150 Middletown [?]
1290 West Hartford [With WCCC-FM, I believe]
1360 Hartford [at WDRC-AM/FM studio in Bloomfield]
1410 Hartford [Cedar Street in Newington]
1550 Bloomfield/Hartford [?]
On the AM side, the only station which seems to cause trouble is WPOP-AM 1410. I can sometimes hear them on a couple of other spots on the AM dial, since I'm no more than 3 miles from their Newington transmitter. It's along CT Route 175, just east of the CCSU university campus. The problems are usually with their daytime pattern, so I must be in a lobe (I'm to its southwest). The interference is to the point to where WMMW-AM 1470 of Meriden gets washed out by WPOP-AM (but also WMMW-AM is only 1,000 watts).
92.5 Waterbury/Hartford [West Peak in Meriden]
93.7 Hartford [West Peak]
95.7 Hartford/Meriden [West Peak]
96.5 Hartford [Avon Mountain in Avon]
100.5 New Britain/Hartford [Rattlesnake Mountain in Farmington]
102.9 Hartford [West Peak]
104.1 Waterbury/Hartford [West Peak]
105.9 Hartford [West Peak]
106.9 Hartford [Off of US 44 near Avon/West Hartford line]
The major AM stations here are:
840 New Britain [Willard Avenue in Newington]
910 New Britain [Radio Park in Farmington]
990 Southington [south end of Southington?]
1080 Hartford [Avon Mountain in Avon]
1120 Bristol/New Britain [?]
1150 Middletown [?]
1290 West Hartford [With WCCC-FM, I believe]
1360 Hartford [at WDRC-AM/FM studio in Bloomfield]
1410 Hartford [Cedar Street in Newington]
1550 Bloomfield/Hartford [?]
On the AM side, the only station which seems to cause trouble is WPOP-AM 1410. I can sometimes hear them on a couple of other spots on the AM dial, since I'm no more than 3 miles from their Newington transmitter. It's along CT Route 175, just east of the CCSU university campus. The problems are usually with their daytime pattern, so I must be in a lobe (I'm to its southwest). The interference is to the point to where WMMW-AM 1470 of Meriden gets washed out by WPOP-AM (but also WMMW-AM is only 1,000 watts).
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