Favorite LPFMs

This topic contains 7 replies, has 5 voices, and was last updated by  Andy Brown 4 years, 11 months ago.

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  • #3487

    Alfredo_T
    Participant

    I was wondering if any of you are fans or regular listeners of the various LPFMs that have come on the air in recent years.

    Previously, I’ve mentioned that I like the forgotten oldies, “scratchy ol’ 45s,” and radio news on KQSO and KQRZ. I need to add KXRY to the list, now that I can hear them on the westside on the 107.1 translator. On Thursday night, they had a show with a bunch of cool French new wave and synthpop from the 80s.

    #3488

    jr_tech
    Participant

    Indeed, 107.1 provides some interesting listening!
    Enough signal strength to be easily received with a decent portable in several rooms in my house west of the Hillsboro airport!

    The 60dBu contour does not go past Aloha, so in many places around Hillsboro, I find it quite spotty on the car radio;
    http://goo.gl/maps/MCm9Q

    The old Harvey Marine Bunny just past 209th *Might* get it ok with a decent “rabbit ears” antenna:
    http://goo.gl/maps/qAVAa

    #3518

    greenway
    Participant

    I love 100.7 KQRZ and sure wish I could get it on both floors of my house 🙂

    #4433

    KevanGC
    Participant

    KXTJ 96.9 in my city, San Antonio. Classic Hits/Disco format.
    Only thing is, it’s down right now while they move towers. It will be back soon I hear.

    Webstream: http://67.212.165.106:8008/
    Facebook: http://www.facebook.com/969jamz

    #4456

    Alfredo_T
    Participant

    I’ve been finding that the K296FT (107.1 MHz) signal appears to be more reliable in the northern parts of Hillsboro. It is a bit spotty along TV Highway (Harvey is not happy). The K296FT antenna is non-directional, but I wonder whether it might be mounted on the tower such that the signal strength to the west is degraded. Reception is fairly good to the east.

    Another thing that I noticed recently is that the over-the air pickup used by the translator appears to be a bit noisy. I recall it sounding better when K296FT first started translating KXRY. In some ways, I am surprised that this over-the-air pickup works at all, since the translator is co-located with KGON. The tuner used must have a killer front-end!!

    Although it is not an LPFM due to its antenna height, I was recently very surprised to learn that I can receive KMUZ from my location in Hillsboro.

    #4459

    Andy Brown
    Participant

    “appears to be a bit noisy. I recall it sounding better when K296FT first started translating KXRY.”

    It’s always been a bit noisy and after all, the translator is located well outside the 60 dBu of KXRY’s signal from Rocky Butte. The receiving antenna provides some gain and side rejection, but it is barely achieving full quieting if you listen to it within the translator’s 60 dBu during quiet passages.

    “<KMUZ>Although it is not an LPFM due to its antenna height,”

    Not because of it’s antenna height at all. It is a Class A allocation and it is licensed as a primary service non commercial station, not a secondary service LPFM or translator. It is on the lower end of possible Class A coverage due to protection. It’s height only determines the ERP it can have before it would overlap the stations it has to protect. If it were lower, it would have more power but would still have the same coverage because of the contours of those other stations. As it is, a DA is required to keep its signal compliant, but it is strong in the direction of Hillsboro from its location. I lucked out being able to use Whipper Hill when I did that application because there is nowhere else in the “opening” that would have a chance of getting into Salem and Keizer at all plus Whipper is one of the highest points in the county except for the mountains to the far east. KMUZ won the allocation primarily because that site provided coverage to more people than any of the other competing applications which were located further east near Stayton using more power at lower heights and non directional antennae.

    #4493

    jr_tech
    Participant

    (KMUZ 88.5) “As it is, a DA is required to keep its signal compliant, but it is strong in the direction of Hillsboro”

    Some observations, a “calculation” and a question:

    KMUZ reception indeed, is fairly decent at my location west of the Hillsboro airport. There are no strong co-channel stations on 88.5 to interfere with KMUZ at this location… KPLU (88.5 Tacoma) is considerably weaker and off of the back of the south-pointed antenna. 1st adj. (88.3 & 88.7) stations are to the east, 90 degrees off of the antenna main lobe, and present no problem either.

    The Sony XDR-F1HD tuner that I am using has only a crude 3 bar signal strength indicator, I get “2 bars” on KMUZ. It has been reported that 2 bars indicates a minimum of 29 dBf at the antenna terminals. Adding 3 db of attenuation in the antenna line will drop the indication to 1 bar… so I am estimating that I have 29 + 3 or 32 dBf at the antenna terminals of the F1HD.
    Now, I understand* that dBu=dBf-5.1-G (where G is the gain of the antenna in dBd minus feedline losses). Using 6 dB for G, I get 20.9 dBu from KMUZ at this location.

    Question… does that seem to be correct? Since the 60 dBu contour** of KMUZ barely makes it to the Southern outskirts of Salem, is 21 dBu likely in Hillsboro? Did I screw up? Is the Brian B equation wrong? (scratches head).

    * http://www.ham-radio.com/k6sti/dbu.htm
    ** http://goo.gl/maps/2tVne

    #4494

    Andy Brown
    Participant

    Seems a little high for the distance involved, but I’ll have to get back to you.

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