radio8z

Let’s leave this topic be with what has been said.

Locked.

It is neat to have a transmitter remote from the studio as you have proposed.  I have done this and understand.

But, I am not sure of the design you propose in terms of what you are wanting to achieve.  Why not just mount the transmitter at ground level with the attached antenna base also at ground level?

Your “anechoic” chamber is not likely t…[Read more]

Rich, is the change in slope on the graph at D = 30 meters due to the transition out of the near field into the far field?

In addition, my installation is reasonably described by Rich’s model for this calculation and I know this because I have measured the loading coil RF resistance and ground system RF resistance.  The physical description…[Read more]

The suggestion posted earlier in this thread that Tim could produce and publish/sell a calibration chart for a particular brand of radio with a built in signal strength meter correlating the reading with field strength sounds good at first read but it is not workable.

The reason is that unless a chart is made for a specific radio (not brand or…[Read more]

I think some of us need to calm down.

It remains business as usual around here.

I am trying really hard to understand why someone new to Part15 and seeking advice would care about this.  They search a bit and find this site and this is what they see.

I am old to the activity and I don’t care about this.  It adds nothing of value to my interest in Part 15 radio.

Artisan,

I have been thinking a bit about your observed increase in range gained by elevating the end of your antenna above the roof line.  One thing came to mind, namely, near field effects, which could be one of the mysterious other factors alluded to.

Did a bit of reading about this and in the near field much of the energy is contained in…[Read more]

“As for considering Part 15 a boundary condition, I would venture to say that a radio signal that is generated by at most 1 milliwatt (0.001 watts) of output power (probably much less) would have the potential to behave somewhat differently than that generated by even the most underpowered licensed station of about a kilowatt (1000.0 watts) – y…[Read more]

I am interested to know re: “…and Part 15 broadcasting is certainly a boundary condition for radio signals”  what you mean by boundary condition?

In mathematics, boundary conditions are used in the solution of differential equations.  I recall spending many days grinding out by hand the solution to temperature distribution in a metal plate a…[Read more]

I just spent 20 minutes on a reply in this thread and even used CTRL-A routine and the text was lost.  I might or might not try again to post it.  Right now I am not in the mood.

Neil

Some info for Rich Powers and anyone else who is interested.  When the Part15.us site was hacked the moderators and administrator lost control of the site and the only option was to take it down.  The site owner and administrator decided the best action was to build a new site rather than to repair and continue using the old software which had k…[Read more]

Carl, I agree with “An amplifier can be truly linear with poor transient response, but the quality of signal would be impaired.”  What I had in mind when I wrote “Linearity and transient response are not related.” was that achieving one in a design does not guarantee the other which agrees with what you wrote.

Further commenting on this, simp…[Read more]

Tell an engineer to design something which “pleases the ear” and you will likely elicit a response that they will produce a device which does not “color” the signal.  What that could mean is that the device will not add distortion or phase shift.  This pleases the engineer’s eye as they view the oscilloscope yet volumes have been written about t…[Read more]

TheLegacy wrote : “…a solution and that was to put the antenna up in the attic? Yes it may cut the range a bit but surly will be better than that wire antenna inside your house. ”

Can you actually demonstrate that an antenna in the attic will provide more range than the “wire antenna inside your house.”

Maybe the “wire inside my house” doesn’t…[Read more]

Carl posted “One thing that was important to notice is that the numbers on the dial top off at 1600, so maybe this radio doesn’t capture the X-band ? (1610-1710?)”

It is very easy to tune this typo of radio to receive above 1600 kHz.  Done it many times.

Brooce,

Tube type or transistor?

Recapping tube radios is more involved because the leakage through coupling caps can destroy tubes so these, as well as electrolytics, generally need to be replaced.  The leakage currents are much higher in tube units because of the high voltages involved which are not found in transistor units.

On transistor…[Read more]

Radio Joe,

Now that’s some serious car radio collecting.  You are doing it right.

Brooce,

The antenna for my radio was just a whip in the basement and since my favorite station was strong I stagger tuned the IF to widen the bandwidth.  There is a trade off between bandwidth and sensitivity so I sacrificed sensitivity hence the radio was not g…[Read more]

Here it is!

It was mounted so that the front of the radio where the speaker mounts fires frontward out of the radio toward the front seat from just under the dashboard.  It has no speaker and I don’t recall but it was probably trash and I removed it and used the external speaker.