TEK NET
The Henderson Amateur Radio Club is pleased to present our Tek Net every Sunday evening, starting at 8pm local time (0300 UTC).
The audio portion of the Tek Net will be found on the Henderson Amateur Radio Club Repeater Network (RF). The audio may also be accessed via Echolink (W7HEN-R node 740644) and Allstar (node 44045).
The audio will refer to this page, so that the listener can more fully understand the concepts as they are presented.
All are welcome!
July 9, 2023
Adding the Motorola POWER VOICE amplified speaker to your mobile setup.
Motorola has for many years advocated that they don’t make products for ham radio use.
Although back in the 1980’s Motorola did make a VHF 25watt mobile ham radio (surprisingly it looked just like the Motorola VHF Marine radio offered at the time, it was too expensive and was limited to 12 channels, all crystal controlled.
It didn’t last and that was the last of Motorola ham radios.
The Cellular Mobile Phone epidemic started in the later 1980’s with the Motorola Pulsar II trunk mount cellular phone. With this phone came a 12 watt Power Voice speaker, to allow hands free operation.
These box shaped speakers had plenty of volume and I wasted no time wiring one up to my ham radio mobile rig.
These older style box type speakers can be found online and at swap meets for a very reasonable price.
They operate off of +12 volts DC and accept audio levels up to 1 watt input. There is a potentiometer inside to adjust the input drive level.
Most import radios have audio levels in the 250-500Mw level, perfect for driving these speakers.
This HSN1000BR isn’t the only amplified speaker from Motorola. Doing a search online will return many model numbers but they are all the same on the insides.
The newer styles are 6 watt versions in the slimmer all plastic housing, normally Black or dark Brown in color, if it has the 6-pin small Molex connector its a Power Voice speaker.
If it’s an older style as pictured above the housing is white and made of aluminum with a white plastic front grille. This is the 12 watt version and will have the same 6-pin Molex connector.
It doesn’t take a lot of work to make these amplified speakers come to life.
The 6-pin Molex connector is a standard item at Kiesub Electonics, so making up an interface cable to connect to your Icom, Kenwood or other brand mobile radio won’t be difficult.
I suggest that you connect the (+12 Volt DC) input lead to a switched 12 volt point in your car (cigar lighter jack) so it comes on and off with the ignition switch, otherwise you should run the power lead thru a switch to eliminate any battery drain when not in use.
In the past I have opened my mobile unit and soldered a wire to the switched side of the power switch and connected that to the DC input of the Power Voice speaker, that way it came on & off with the radio.
These speakers are available from some online Motorola suppliers with a cost of $106.00 or more. However they are all over the internet or swap meets for around $20 or so.
One of the most appealing features of this speaker is that the circuit and the enclosed 20 watt speaker is designed to reproduce the vocal audio range of 500 hz to 2500 hz, thus giving you crisp clear communications grade sounding audio.
This really helps when a policeman is trying to communicate with the dispatcher while running Code 3 with the siren going, that crisp piercing audio really comes thru.
While you may not have a siren in your vehicle, driving in Las Vegas with the window down can be pretty noisey, this speaker will take care of that.
As seen in the upper left hand portion of the circuit board is the Audio input level adjust control.
I have bought many of these speakers at swap meets for $5 -$10 dollars because the seller said the unit was defective or damaged.
Everyone of these units when checked on the bench were fully operational with the level control turned all the way down.
This is the factory default setting to prevent excessive audio when first powering up the mobile phone. ( too bad the sellers didn’t know that!)
I have been using Power Voice speakers for over 30 years and have never come across a defective or failed unit.
Access to the Audio Input level control is available with a small flat bladed screwdriver thru the access hole on the rear of the speaker by the metal bracket
