Spotted an SFPD unit with a low band whip last week

[TrevDog]

I didn't know that they still ran any low band units. Maybe they've just never taken it off?

[rooivalk]

Originally Posted by TrevDog

I didn't know that they still ran any low band units. Maybe they've just never taken it off?

all cars have a lowband radio, as backup for the questionable trunked system currently in use.

[K6CDO]

Originally Posted by TrevDog

I didn't know that they still ran any low band units. Maybe they've just never taken it off?

San Francisco is a city that remembers history.

Following the 1906 quake, the City built redundant water systems and telephone systems for fire & pd (on City owned copper) that (when I was last in the City) is still in use.

In 1989, both of those systems (water and phone) paid off.
In the mid-1990s, SFPD kept their 45 MHz mobile system as a back-up against a significant failure of the trunked radio system.

[mmckenna]

There is also a low band mutual aid repeater just south of SF. Low band would likely work quite well in the hilly terrain of San Francisco.

[TrevDog]

I see. I appreciate the history of the city, but frankly, this seems kind of ridiculous- from a layperson's perspective, of course.

[mmckenna]

Simplex low band can be a pretty awesome thing with a good antenna.

[n5ims]

Originally Posted by TrevDog

I see. I appreciate the history of the city, but frankly, this seems kind of ridiculous- from a layperson's perspective, of course.

Backup systems are always a total waste of money and resources until they're needed and then they're seen as the best thing that they ever had. It's like buying insurance. A total waste of money until your house burns down or you have any other type of major claim.

[mmckenna]

Originally Posted by n5ims

Backup systems are always a total waste of money and resources until they're needed and then they're seen as the best thing that they ever had. It's like buying insurance. A total waste of money until your house burns down or you have any other type of major claim.

Often the first thing to get "value engineered" out of a project. SF already had it in place, so they avoided that.

[inigo88]

I'm with these guys. Why does it seem "ridiculous?" In Marin County, all the public works users vacated their VHF frequencies and moved to the countywide SmartZone system MERA. Remembering that the MERA system had completely failed several years prior (including all the back-ups and redundancies) right in the middle of a countywide emergency, the fire chief's association quickly acquired all those VHF licenses. Since they already had VHF mobiles and portables for interop with CAL FIRE, they proceeded to build a "VHF Overlay" back-up system of VHF command repeaters and simplex Tac channels that would seamlessly take over should the trunking system ever fail again. That's not ridiculous, that's good planning (and learning from EXPERIENCE)!

[lbfd09]

Yep smart planning, the Loma Preita Quake showed that the microwave and laser links, as well as statelite will go down until someone can travel to the location and re-aline the mess the quake provided. Low band redundency in Californina is a requirement.

Most agencies up here have tried doing it digitally with less, but found out very quicly that would not work in real emergencies. The quicker things that public safety depend upon get back in service, the more lives are saved.

As to the water in the street - they still have those - I saw several the past week, while up there. They also pumped water out of the bay for some of the Maria District fires as I recall. But, that is somewhat limited with the long hose lays.

[Radio_Lady]

Originally Posted by lbfd09

Yep smart planning, the Loma Preita Quake showed that the microwave and laser links, as well as statelite will go down until someone can travel to the location and re-aline the mess the quake provided. Low band redundency in Californina is a requirement.

Is California's HF "STACOM" aka "SECURE" system still operational? Low band propagation and then some! Somewhere online there were recordings of traffic immediately after Loma Prieta between various counties and Sacramento, and if memory serves, NAWAS traffic too.

[mrob907]

Well most Patrol Cars still have the lowband radios installed because, why waste it if we still have it ? The trunked system IS GOING TO CRASH for a little while at least when the big one hits. Until we can get the control channels back on-line for the trunked system, lowband will work great. In fact, from the top of twin peaks, on a perfect day (this was a long time ago) SFPD units could transmit via lowband and send/rcv (due to atmospheric skip of course) to Shreveport, Louisanna PD who shared some of our same freqs. Didn't happen often, but often enough to happen !!

[Exsmokey]

Originally Posted by lbfd09

Yep smart planning, the Loma Preita Quake showed that the microwave and laser links, as well as statelite will go down until someone can travel to the location and re-aline the mess the quake provided. Low band redundency in Californina is a requirement.

Most agencies up here have tried doing it digitally with less, but found out very quicly that would not work in real emergencies. The quicker things that public safety depend upon get back in service, the more lives are saved.

As to the water in the street - they still have those - I saw several the past week, while up there. They also pumped water out of the bay for some of the Maria District fires as I recall. But, that is somewhat limited with the long hose lays.

When Dianne Feinstein was mayor of San Francisco the city council tried to get rid of the fire boats. It turned into quite a fight and she dug in her heals and spoke of the 1906 quake and the failed water system. She said the fire boats could be used to pump large volumes of water into parts of the city. It was a good thing she held her ground given what happened in the Marina District.

[redneckcellphone]

Fighting to keep the fire boats was the only good thing she did for komifrnia


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[kma371]

Originally Posted by mrob907

Well most Patrol Cars still have the lowband radios installed because, why waste it if we still have it ? The trunked system IS GOING TO CRASH for a little while at least when the big one hits. Until we can get the control channels back on-line for the trunked system, lowband will work great. In fact, from the top of twin peaks, on a perfect day (this was a long time ago) SFPD units could transmit via lowband and send/rcv (due to atmospheric skip of course) to Shreveport, Louisanna PD who shared some of our same freqs. Didn't happen often, but often enough to happen !!

what makes you think the radio system is going to crash in the event of an earthquake?

[redneckcellphone]

No one is sure if or when the "big one" is gonna hit. But a few years ago when we had an earthquake that wasn't even as big as the northridge quake the cell towers went down. So yeah it's nice to have a backup.


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[K6CDO]

Originally Posted by kma371

what makes you think the radio system is going to crash in the event of an earthquake?

It doesn't necessarily take an earthquake. Other factors which can crash a system include:

• Human error
• fire at a critical site
• critical component failure

System operators plan for these contingencies. San Francisco's planning includes secondary radios.

[kma371]

Originally Posted by K6CDO

It doesn't necessarily take an earthquake. Other factors which can crash a system include:

• Human error
• fire at a critical site
• critical component failure

System operators plan for these contingencies. San Francisco's planning includes secondary radios.

I understand all that but he made it seem there would be an automatic failure in the event of one.

[Exsmokey]

Originally Posted by redneckcellphone

Fighting to keep the fire boats was the only good thing she did for komifrnia


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I did not mean to make a political support statement for Dianne Feinstein. I was just relating that sometimes it is good to keep what might seem outmoded. The increased complexity of radio and dispatch systems is allowing great strides to be made in emergency management. Keeping some backup in command centers such as HF and/or low band simplex radio that requires nothing other than a generator and an antenna to operate is likely prudent. A backup system of keeping track of resources, such as the T card system ICS uses when computers running the ROSS system cannot be brought to the scene should also be provided for.

We haven't really seen the type of disaster that is possible and according to some probable in the foreseeable future. What we have experienced in the last decade have shown us how to improve backup systems, but always count on the unexpected or inconceivable when preparing for disasters.

“It wasn't raining when Noah built the ark.” Howard Ruff

“I know not with what weapons World War III will be fought, but World War IV will be fought with sticks and stones.” Albert Einstein

[redneckcellphone]

Yeah not a fan of her lol. But yeah look at hurricane sandy. Most of the local comms were done on simplex and some were even using hts on amateur band. Still sitting here waiting for the big quake to hit lol


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