Well West Covina is FCC license rich, but who knows if any are active or not.
You can trying checking out the following.
KAZ313
154.070
154.280
154.310
159.015
KD46068
155.34
KMA449
154.725
155.790
KQB52
155.430
KTS740
154.070
WNNF953
855.4875
WQKK264
154.310
If you find anything, kindly submit to the Db.
I can provide a little insight into that license richness, if anybody wants it.
In the eastern San Gabriel Valley, Azusa, Claremont, Covina, Glendora, La Verne, Pomona, and West Covina used to share one police dispatch frequency: 155.4900. Another block of cities, including El Monte, Irwindale, Baldwin Park, Huntington Park, etc., shared 155.7900. In time, and due to ever-increasing radio traffic, the departments on 155.4900 migrated to their own frequencies. By 1974, Pomona had moved to 155.5500 MHz, and West Covina had departed from the large group of cities on 155.4900 MHz to join the smaller group (El Monte, Irwindale, Baldwin Park, and Huntington Park) on 155.7900 MHz.
Later still, after 1976 (when the T-band became available), even more changes happened. Covina moved from 155.4900 to its own frequency (154.7250); Claremont left 155.4900 for its own UHF frequencies; and Azusa and Glendora together went to their own shared 154.8450 frequency. This left La Verne alone on 155.4900. During this same period, West Covina, Irwindale, and El Monte likewise left 155.7900 for their own UHF systems, leaving Huntington Park alone on 155.7900.
Most recently, Azusa split away from Glendora, obtaining 155.9400 for itself; and La Verne abandoned 155.4900 entirely, moving to UHF. (Covina now uses 155.4900 as its second channel. It never dumped its license for it, and once La Verne let it go, it became theirs.)
In any case, a similar arrangement existed with many of the fire departments in this area. I'm not as clear on these details as I am with the police departments, but as one example, many of the eastern San Gabriel Valley cities shared 154.0700 for fire dispatch, and another block of cities further to the west shared 154.3700. They used to be called "red east" and "red west," if memory serves. LACoFD now has them both.
Getting back to the subject of this thread, West Covina, for whatever reason, simply seems to be one of those cities that clings to many of its old licenses.
Going over LAFlyer's list:
154.070 - dates to when the eastern San Gabriel Valley cities still had their own FDs (with many using this for dispatch). Since LACoFD now uses this frequency as a fireground in this area, WCFD probably still has it in its VHF radios for mutual aid -- assuming it still has any VHF radios.
154.280 - same origins as the above (when the cities sharing 154.0700 for dispatch still did so, many also used 154.2800 as a secondary for fireground). This frequency too may still be in WCFD's VHF radios, if they have them, simply because it's a statewide MA frequency.
155.790 - old PD dispatch frequency in the West Covina + Irwindale + Baldwin Park + Huntington Park era. No idea why they maintain this license whatsoever; the only remaining user is Huntington Park, which is quite far away, in mutual aid relevancy terms.
154.725 - dates to the above era (for mutual aid with Covina after it moved to 154.725). If the WCPD still has VHF radios, they may still keep this in them for Covina's sake.
As far as the others:
155.430 - CLERS Los Angeles input (output is 158.79) (it's a dispatcher-to-dispatcher network)
155.34 - a HEAR frequency (WCFD is also the city's ambulance service, so this makes sense)
855.4875 - MDTs
159.015 - Input to 156.165 repeater (156.165 is now WC's public works -- it was formerly WCFD channel 1)
154.310 - This is the only one that's still a mystery to me. Up until a couple years ago, WCFD used 156.165 for channel 1 (dispatch), and 154.310 for channel 2 (fireground). Both were simplex. Meanwhile, public works had 506.4875 (repeaterized). Then they traded radios. WCFD took over 506.4875 as their repeaterized dispatch frequency (and added 460.3375 as a new repeaterized fireground). Public works, in turn, added repeaterization to 156.165 and took it over as their main frequency. 154.310 was also repeaterized (it has an FB2 license with the FCC), but no input frequency ever showed up in the license records.
Oh, right. WCFD is also licensed for all the UHF MED frequencies. And finally, WC also has a license for 155.715, which was one of their VHF-era PD secondary frequencies. (5-10 years ago, I used to hear their special enforcement team and detectives using it for simplex special operations. No idea whether it's still in use.)