Carl Blare

Our 1640 AM transmitter is fed by an FM signal at 85.5 MHz coming from a C.Crane FM transmitter, but the stereo sub-carriers are putting “birdies” on the AM signal.

Our 1640 AM transmitter is fed by an FM signal at 85.5 MHz coming from a C.Crane FM transmitter, but the stereo sub-carriers are putting “birdies” on the AM signal.

Is there a known way to shut off the stereo on the C.Crane and transmit in mono?

I spent the day assembling our second Ramsey FM25B.

I spent the day assembling our second Ramsey FM25B.

The first one we had was good but I gave it to someone who wanted FM in the house. The only thing I remember about it that I’d criticize is poor low frequency in the audio. Otherwise it was frighteningly powerful even with the antenna retracted and the power control minimized.

Although also called 25B, this new one seems different somehow, and better! The audio is spectacular. The strength is way beyond the C.Crane, which I purchased as a guidepost so that a certified transmitter could be used as a point of reference. Unfortunately it’s been raining for three days, so I can’t walk the neighborhood with a portable.

Earlier this week I toyed with the C.Crane FM transmitter and found that adding 1/2
wave or full wave antenna lengths finally gets it to the rooms of the house with a minimum of dropouts. I have a hunch that the output is intentionally reduced to safeguard against people who add antenna length.

Thoughts?

This question is too general to attach to any particular Forum thread, and not worthy of starting a new Forum thread, so here it is as a Blog entry:

This question is too general to attach to any particular Forum thread, and not worthy of starting a new Forum thread, so here it is as a Blog entry:

It would be handy, at times, to have an extender for an ordinary telescoping antenna. It seems to me an additional 1 1/2 foot telescoping antenna with two appropriate clips could be a useful experimenter’s device.

Has anyone seen such an accessory?

On a recent Blog Neil gave me an idea how I could reach a woman living just outside of transmitter range by going there with a boom box, but I’ve lost touch with that Blog entry, to which I am here to add an update.

As one thing leads to another I ended up taking a neighborhood walk with the very woman and she took quite an interest in Part 15 low power broadcasting, which I naturally talked about in some detail. She was fascinated by the seeming magic of being able to send talk and music out through the walls and into the yard.

As time goes by maybe there’ll be a new member joining Part 15.

Lobbying for a good hobby.

At last I thought I was hearing an actual Part 15 station other than my own. The radio was still set to AM 1680 hours after KDX, my toy station, had left the air. Like probably most of true radio types I enjoy hearing that background garble during odd hours. All of a sudden words started jumping out from “Public Reality Radio” WPRR 1680 AM. They gave a website, publicrealityradio.org and the website could easily be taken for a Part 15 operation, especially the program schedule, containing many of the exact programs carried by a whole lot of Part 15ers and streaming internet stations. But radio-locator.com actually lists a WPRR, 1680 KHz in Ada, Michigan, with 10 kw day and 680 watts night. How unusual.

Previously we set forth the idea of loading every open channel with a Part 15 signal, hoping to compensate for weak signal with plenty of signals. The ideal way for the average home occupant to achieve this would be in minimal architectural space, namely from a single antenna cluster acting like a big frequency sprinkler. But it don’t work.

The closer frequencies are to one another, the more are “tuned” antennas inclined to receive and transmit at the same time. Example: when my 1550 KHz and 1680 KHz antennas are mounted on the same pole, they back-feed into each other and are no longer separate, discreet signals. Each one carries a trace of the other. This becomes very obvious when different audio is sent over each transmitter. The only solution we know is to separate the two transmitters as far apart as possible. Of course ultra-precise filters could be designed, but now we’re talking about cutting into the bandwidth of the antennas, and we’re not that smart.

Luckily this can be expressed philosophically:

The solution to one problem is the problem to another solution.