"New" Part 15 Station in Alameda, CA

[Dave Richards]

I put the word new in quote marks because although this Part 15 installation is new, it is acting as a relay for Radio Sausalito programming. For anyone who isn't familiar with Radio Sausalito, it has been on the air for around 25 years now, serving Sausalito, Marin City, and a small part of Tamalpais Valley, with a network of 6 Hamilton Rangemaster transmitters on 1610AM. For anyone wanting more information, I hope Chris won't mind if I share the link to this article that I wrote for Hobby Broadcaster some years back -

https://www.hobbybroadcaster.net/profiles/radio-sausalito.php

A few months ago, I read that the California Historical Radio Society in Alameda were now relaying the Radio Sausalito programming from their headquarters on Central Ave in Alameda, on 1570AM. I have visited CHRS many times. They have great events, and vintage radio swapmeets and auctions, as well as a fascinating permanent collection of vintage radios, TV's, and a well-stocked library. They are building a wonderful museum of the golden age of broadcasting.

Anyway, knowing that they now had a Part 15 station on the air, I couldn't wait to check out the coverage. I spent both afternoons this weekend walking around the city of Alameda with a couple of receivers and a pair of earbuds, and had a very rewarding time. Alameda is on an island in the San Francisco Bay Area, immediately south of the city of Oakland. Access is via both a bridge and two underwater tunnels linking Oakland to Alameda. Although very close to Oakland, Alameda has a very different feel - sort of a "small town in a large metro area" vibe. It has a lot of lovely old Victorian houses, and a distinct sense of it's own identity. A Part 15 station gave me the perfect excuse to spend time walking all around Alameda, so that I could check out the various streets and areas, while listening out for the Radio Sausalito relay signal on 1570 AM.

I took two receivers with me - a C Crane Skywave SSB, and a Belka-DX. Both are sensitive and selective receivers. While walking around, I listened to both with a pair of C Crane earbuds, which are optimized for voice. They're really good for listening to Part 15 signals, as the frequency response de-emphasizes any noise underneath the carrier. I walked about 10 miles over 2 afternoons, listening all the time. Basically, there was listenable coverage outside over the entire east half of the island, which is where the majority of the businesses and residences are concentrated. CHRS is conveniently located roughly halfway between the north shore and the south shore. The distance from the top to the bottom of the island  is about 1.5 miles, and the signal covers that entire span. From side to side (very approximately east-west), the signal can be heard all the way to the east shore in one direction, and about a mile to the west in the other direction. To the south, the signal probably spills over into the bay, though I didn't commission a boat to check! On the north side, I imagine the signal can just be heard in Oakland, at the other side of the narrow channel separating Alameda from Oakland.

The coverage map shows the area in which I received a signal that could comfortably be listened to outside. The blue dot shows where CHRS is, where I assume the transmitter is located. I'm not sure what the signal was like indoors over the whole coverage area. However, I sat inside a Starbucks on Park Street, which is the main shopping and dining street. I was 1700 feet from CHRS, where I assume the transmitter is, and sitting next to a window. I was receiving a strong signal with virtually no noise. There possibly was a little smooth noise, but it was masked by the modulation. All in all, it was an impressive signal coming from what I assume is less than 100mW into an electrically very short antenna. I don't know anything about the transmitter installation, but CHRS counts among it's members a number of broadcast engineers who undoubtedly understand the importance of a good RF ground to an AM signal.

It's great to have a Part 15 station so close to home; one that looks as if it will be around for the long term. It has inspired me to look for ways to improve the coverage of my little station. My signal is nowhere near as impressive as the one from 1570AM in Alameda.

[tybee]

Wow David, thanks for posting this, I hadn't even caught wind of it! However, it appears it isn't just a rebroadcast but a partnership because the Almeda historical society is also incorporating  some of their own programming into the broadcast..

●Radio Sausalito From Radio Central
SAUSALITO, CA
October 3, 2024
– Bay City News is expanding beyond the written word to bring local news and arts reporting to Radio Sausalito. The partnership, a first of its kind in the region, brings together two different but independent community media voices. ...
https://californiahistoricalradio.com/2024/10/radio-sausalito-from-radio-central/

A couple others:

●California Historical Radio Society in Alameda honors medium’s legacy
October 15, 2024
..Alameda’s California Historical Radio Society (CHRS) headquarters, affectionately known as “Radio Central.”.. Started in 1974 and originally housed at the former KRE radio studios next to Berkeley’s Aquatic Park, ...The approximately 600 CHRS members are in the process of refurbishing the building to its original state. Upstairs visitors will find a museum-quality collection of early radios ..They even have a fully functioning radio studio, which isn’t just for show. The studio broadcasts the signal of Radio Sausalito, an online and on-air jazz station at 1610 AM in southern Marin County. The broadcast signal from the Radio Central studio can be heard.. at 1570 AM...
https://www.eastbaytimes.com/2024/10/15/california-historical-radio-society-in-alameda-honors-mediums-legacy/


●History of radio thrives in hidden Bay Area museum
Bay Area News Group
May 26, 2024
SAN JOSE, Calif. >> Walk into a nondescript building in Alameda, Calif., — ...an institution devoted to everything under the sun related to wireless communication, stretching back some 120 years to the invention of radio.. ..and a soon-to-deploy station at 1570 AM that will play old jazz records on old equipment...
https://www.staradvertiser.com/2024/05/26/travel/history-of-radio-thrives-in-hidden-bay-area-museum/

[Dave Richards]

Thanks for that Rich! I missed the part where CHRS said that at some point, they would be contributing programming. It makes sense because, in the museum, they have created an on-air studio using vintage equipment -

[tybee]

Well, not at some point, they already have (as described in my first link above). Two of their programs have been airing since September:

“Local News Matters,” is a weekly roundup of reporting by independent journalists featuring stories affecting Southern Marin and the greater Bay Area. 

The second show, “Bay City Beat” is hosted by Leslie Katz and showcases a unique listing of weekend arts and cultural events around Marin County and the Bay Area."[/I

Those are some cool pictures of the studio and equipment, you take them yourself when you were there?

[Dave Richards]

I saw that Rich, but don't see any evidence that the two new programs referenced are linked to the California Historical Radio Society (CHRS), or are happening as a result of this new partnership. Perhaps I missed something.

I visit CHRS quite often. It's just a few miles down the road from where I live. Yes, I took those pictures at their annual "Radio Day by The Bay" a couple of years ago. The place is chock full of artifacts from the golden age of broadcasting. These pictures are just part of one room in the building; there is a lot more to see.

It's good to see Radio Sausalito not only still in existence, but thriving and expanding after over 20 years on the air. This would seem to be a textbook example of how to build a long-term, healthy organization around a Part 15 station. Many Part 15 stations are one-person affairs. Even more are simple vanity projects (like my station!) It's no mean feat to build a team of volunteers to continue contributing to a station over a long period of time, and to keep it running. Quite an achievement.

[ChrisSmolinski]

Thanks for the very informative post!  They're getting great coverage, which shows what 100 mW and a few feet of wire can do.

[tybee]

I saw that Rich, but don't see any evidence that the two new programs referenced are linked to the California Historical Radio Society (CHRS), or are happening as a result of this new partnership. Perhaps I missed something.

No you didn't miss anything. It's me who misunderstand CHRS article. Its actually two reporters from Bay City News thats partnering up with Radio Sausalito and producing the new programs..

Anyway thanks again for posting about it. I had totally missed the story altogether.

[Dave Richards]

I'm just happy that I came across something before you did Rich. You're the supreme documenter of all things Part 15! I only knew about it because it's right in my back yard, and I'm already familiar with CHRS.

I'm heading to the army surplus store in Oakland today, to look for a new pair of pants. It just occurred to me that it is right across the narrow channel of water that separates Alameda from Oakland, so I'll get a chance to see if coverage of the Radio Sausalito relay station extends to the mainland at all. Being a radio geek is fun!

[Dave Richards]

Very interesting day today. I did some listening to this station in the part of Oakland that is just across the water from Alameda. At some point, I may listen in enough different areas of Oakland so that I can draw a new coverage map. Today, I concentrated on a few specific areas and just one main street, Fruitvale Ave, in the Fruitvale area of Oakland.

Reception was good and very listenable in the area of the Embarcadero in Jingletown, by the waterfront. I then walked away from Alameda (and also away from the transmitter), up Fruitvale Ave. Without detailing the exact locations I was taking reception readings (because few readers will be familiar with this area), I found the following. Reception was good, with only smooth noise in the background that was not very noticeable, up to about 1.25 miles from the assumed transmitter location. From there to about 2 miles away, reception was fairly listenable, with about 40-50% noise on the signal. The signal became increasingly less consistent, with deeper nulls, but some surprisingly strong peaks until, at about 2.4 miles, the signal became discernible but not what I would call listenable.

What I was completely unprepared for was when I got home, I discovered that I could just about discern the station outside my house. The signal was just strong enough for me to make a positive ID from the music they were playing. Not sure if I'd have been able to adequately hear speech though. My house is 3.3 miles from the assumed transmitter location. Even more amazing, is that they picked such a clear channel, I can just about ID the station after dark from my house. It's definitely not listenable though!

When I first decided on the frequency I wanted to use for my station, thinking of antenna efficiency, I only looked at frequencies at or above 1600KHz. I now wish I had looked a little below too, as 1570 in this area is an excellent frequency for Part 15. It works well for CHRS, as many of the restored vintage radios they have in their collection, or that they have sold to locals who live nearby, will be able to receive the station - a good argument for them not choosing a frequency in the expanded portion of the band.

[tybee]

...wish I had looked a little below too, as 1570 in this area is an excellent frequency for Part 15. It works well for CHRS, as many of the restored vintage radios they have in their collection, or that they have sold to locals who live nearby, will be able to receive the station - a good argument for them not choosing a frequency in the expanded portion of the band.

Really good point. You'll might lose a some potential range going below 1600, but when you consider that most old radios  cant receive the expanded bands -- it seems such a shame.

This first occurred to me many years ago when a yearly vintage car event was taking place on the island, and they had those stock AM radios playing in their cars, but they couldn't tune me in on 1700

It just seems wrong.

Another thing, if you want to buy ultra cheap AM radios as giveaway swag then they'll going to be coming from China, and I notice most of them dont ho above 1600 even today.

Unfortunately I'm going to have to stick with 1700 for the time being because it's the only crystal I have! I did have a 1630 but I'm afraid its lost, as I've no idea where it went and never even used it.

[ThaDood]

That is cool what Dave Richards has got going, and Boomer, of AM690, noticed that there's great soil conductivity there for Part 15 AM to reach-out. (Unlike where I am in WV, where soil conductivity is maybe one-step up from a desert.) As far as Tybee not having a crystal for 1630kHz? One option is a cheap DDS, (Direct Digital Synthesis. ), VFO, and feed that to the crystal socket.  Boomer, of AM690, uses that as his fall-back option, when a crystal OSC fails on him. Passing contemplation. Even, to hack a PLL, (Phase Locked Looped.), based tuner's Local Oscillator, and feed that to the crystal socket. There's a will, today, there's a way.

[tybee]

It seems with all the crystal manufacturing for the hobby toy phanes and cars anyway, why m as nufacture a few short runs for the AM expanded bands at the same time,?

What's so difficult about cutting Crystal's anyway? Didn't hobbies use to do it themselves in days of ols?

[Dave Richards]

ThaDood - yes, DDS is the way to go to replace a crystal, IMHO. The agile frequency module in the Rangemaster uses a little SMD clock generator IC that is programmed by 2 banks of DIP switches. I used to think it was a PLL circuit, but I looked at the IC in mine this morning and looked it up online. I think this is a slightly different method of frequency generation from DDS, but it seems to work well. You could pair up an Si5351 clock generator IC with an ATMega325 processor for a little circuit that would act as a crystal replacement. Adafruit sell an Si5351 breakout board, which you could team up with a cheap Arduino Nano. Then you just program whatever frequency you want into it. For greater stability, you can use a TCXO instead of the regular reference crystal.

From the point of view of circuit simplicity, I like crystals. Nowadays, for anything other than very specific frequencies, for which they are manufactured by the boatload, crystals seem to have gone the way of the dodo. I don't fully understand why Keith no longer uses crystals in his Rangemaster though. I'm a radio ham, and there are a few vendors who have bulk lots of crystals manufactured for specific popular frequencies in the ham bands, and sell them individually to hams - 7030, 10106, 14060, 21060, and 28060KHz, for example. I'm wondering why Keith couldn't have done this for the channels from 1590KHz thru 1700KHz? I believe that the crystals in the Rangemaster were HC-6/U types, with pins. I notice that the custom ham crystals that are now available are in smaller cans with wire leads - not pins. I wonder if it's the cans with pins that are no longer available for custom orders? The market for hams is probably bigger than that for an individual Part 15 transmitter builder, so it could also be the case that the minimum order required is too big for a Part 15 transmitter manufacturer.

As far as grinding your own crystals Rich, that was done with the older crystals that were in bigger holders that could easily be taken apart and reassembled. The FT-243 crystal was a popular size. The side plate on the holder could be unscrewed, and the little slab of crystal was held on to the wire connectors with a compression plate. It was a relatively simple matter to remove the crystal, grind it down a bit to increase the frequency, and reinsert it. You could even decrease the frequency a bit by rubbing graphite (from a pencil) on the side of the crystal. However, there was a limit to how much a crystal frequency could be moved with this method. You wouldn't have been able to move an AM BC band crystal one whole 10KHz channel - it's just too big of a frequency excursion.

[Dave Richards]

I guess this post could be considered a logging. Not many folk post loggings of Part 15 stations, so I'll put mine here. I think it's interesting to share information on how far away Part 15 stations can be heard. Yesterday, I was walking around the area of Oakland near where I live and was able to hear them. The signal was very weak, but identifiable, at a distance of 5.1 miles from the transmitter. Receiver was a handheld Belka-DX with the telescopic whip.

I'm curious to see if it can be heard at greater distances. I'll add to this thread if I hear it any further away. In the image, the vertical black line shows the direct path from the believed location of the transmitter (at the bottom) to my receiving location.

[ChrisSmolinski]

Your coverage area results of this station is beginning to convince me that my local 1620 WEDG may indeed be Part 15 compliant! Well, as compliant as possible, anyway