Junk box.

[KA5PIU]

Hello.

Hams have them, that parts supply with parts from who knows what.
But, where do you get the parts? everything is is so application specific, right?
Well, for starters, microwave ovens have this wonderful HV supply, DC even!
But, there are other sources.
One apartment complex had four cordless electric lawnmowers that they were junking.
I just had to take a peek.
Inside two are 24 volt Li-Ion packs and the other two have NiMH packs.
The charger on three are the same, just a jumper setting for battery type.
The electric motor in each one is the same.
After a bit of work I was able to remove the motors, each one is fine.
The battery packs are defunct but everything else works.
So, I converted two to corded electric power, not that I do not have enough mowers.
One of the chargers I am using as an aircraft NiCad or lead acid 24 volt charger, switch selectable.
The other three are junk box items at this time.
But, so far everything has been free.

[12Footer]

I found a cordless drill on the side of the interstate today. The case is toast, but -- I'm thinkin "homebrew screwdriver mobile antenna" some day. :monkeydance:

[N8YX]

I found a cordless drill on the side of the interstate today. The case is toast, but -- I'm thinkin "homebrew screwdriver mobile antenna" some day. :monkeydance:

Get the 7th edition ARRL Antenna Compendium - two "screwdriver" construction articles featured therein.

FWIW: There was an entire truck load of new, 12v cordless high-torque screwdriver sets offered for sale at a local motorcycle swap meet a couple years ago. Price, including set of bits: $1.50 per kit.

[N2CHX]

Price, including set of bits: $1.50 per kit.

Wow, that's CHEAP! My bits just went for about $10,000.

[KG4CGC]

:rofl:

Wow, that's CHEAP! My bits just went for about $10,000.

:rofl::rofl::rofl::rofl:

[N4VGB]

I found a cordless drill on the side of the interstate today. The case is toast, but -- I'm thinkin "homebrew screwdriver mobile antenna" some day. :monkeydance:

Screwdriver antenna = air cooled dummy load that just happens to very slightly radiate RF.

Military whip with autotuner located at base, the only way to fly.

[N8YX]

Military whip with autotuner located at base, the only way to fly.

'WIK's test-range evaluation of a base-loaded arrangement like you describe says otherwise.

As do my experiences.

A whip/tuner combination works well at the resonant frequency of the whip but as you go lower in frequency the losses go up. In some cases, way up.

[KC2UGV]

Screwdriver antenna = air cooled dummy load that just happens to very slightly radiate RF.

Military whip with autotuner located at base, the only way to fly.

Military whips are pieces of 吹牛・吹牛. The splinter and crack constantly, and even the vhf ones are worse than 廢物・废物, because they detune constantly while driving, killing the finals in the rigs.

[N4VGB]

Military whips are pieces of 吹牛・吹牛. The splinter and crack constantly, and even the vhf ones are worse than 廢物・废物, because they detune constantly while driving, killing the finals in the rigs.

Oh BS Corey, you can't even build a 20m dipole that works worth a crap!:rofl:

I've used a Shakespeare fiberglass military whip with an Icom tuner at the base for years. Mounted to an ARA fiberglass bed cover shell on a '93 Chevy 4WD truck. 16ft and tied down to the front bumper in NVIS configuration while moving, add the larger base sections while parked for 32ft total.

The only real problem is if someone is operating it on 160m while parked, the RF voltage is real high at the exposed 4 ga hard drawn copper wire connecting the base of the antenna to the tuner inside the shell. It'll eat your arse alive at the base while xmitting. Hands off dummies!:rofl:

[N4VGB]

Originally Posted by N4VGB
Military whip with autotuner located at base, the only way to fly.



'WIK's test-range evaluation of a base-loaded arrangement like you describe says otherwise.

As do my experiences.

A whip/tuner combination works well at the resonant frequency of the whip but as you go lower in frequency the losses go up. In some cases, way up.

Did you know that I can't do a "Reply with Quote" to any of your posts???

I do a lot of things differently from what the "antenna experts" say to do. I don't believe in tuners in the shack at all or at the radio in mobile use. A tuner, to work at it's best, belongs at the actual feedpoint of any antenna. That isn't practical for many installations, but it is very practical to use open wire feeders for any home antenna and use coax to only feed the tuner.

With a tuner in the shack you're tuning your coax run as part of your antenna and it will assuredly radiate RF on some frequencies, even if the antenna is cut for single band use.