Has anyone ever seen one of these?

[guitar_199]

It is a Midland branded antenna matcher/tuner.
Not that I really think it would be THAT useful since 11m antennas are typically monoband... and you can tune them to match well on their own .....

I just like knowing about the equipment I have.
It has no "model number" or anything else that identifies it......
Any attempt I have made to search it up...... "nobody's home"!!!!!! It is like Google doesn't know these ever existed.

 

[Handy Andy]

The "Ground Plane - Beam" switch has me curious - so I can understand the desire to know more.

To me, the "Ground Plane" switch was for systems that had an antenna designed for 50 ohms Ω but wern't quite spot on due to issues with moisture rain wind or tuning out TVI...

Same applies for "Beam" - the antenna on that kind of system would / could be resonate, but have an impedance bump requiring tuning into a 72 ~ 75 Ω load "appearance" and again a TVI issue.

The Ground plane approach would be less focused on sharp tuning to cancel out reactive effects of proximity to trees, Other TV aerials - even RFI to other radios (tunable traps) while the "Beam" means what it says, this is for systems that are closer to Dipole operation and have a different impedance when at resonance - this can tune out the reactive effects by changing how "sharp" the tuning controls work with the coax connected to such a system.

The only thing would be to remove the covers and it may answer the reason for the switch - but might not for whom the manufacturer is or possibly drum up any sort of documentation.

These kinds of units are rare and even with Googles resources - is not always searchable.

 

[guitar_199]

It definitely acts as an antenna switch. I neglected to show it.... not on the back are 3 SO239s...... transceiver, ground plane and beam. So the switch really does switch antennas but obviously does not allow for a beam with horizontal AND vertical polarization.

Since it doesn't have any kind of band switch I am going to assume that it can only handle enough adjustment for something on 11m. I still wonder how much power it can take.

Again... I really doubt that I would use it...I had just never seen one as a CB accessory.

The "Ground Plane - Beam" switch has me curious - so I can understand the desire to know more.

To me, the "Ground Plane" switch was for systems that had an antenna designed for 50 ohms Ω but wern't quite spot on due to issues with moisture rain wind or tuning out TVI...

Same applies for "Beam" - the antenna on that kind of system would / could be resonate, but have an impedance bump requiring tuning into a 72 ~ 75 Ω load "appearance" and again a TVI issue.

The Ground plane approach would be less focused on sharp tuning to cancel out reactive effects of proximity to trees, Other TV aerials - even RFI to other radios (tunable traps) while the "Beam" means what it says, this is for systems that are closer to Dipole operation and have a different impedance when at resonance - this can tune out the reactive effects by changing how "sharp" the tuning controls work with the coax connected to such a system.

The only thing would be to remove the covers and it may answer the reason for the switch - but might not for whom the manufacturer is or possibly drum up any sort of documentation.

These kinds of units are rare and even with Googles resources - is not always searchable.

 

[AudioShockwav]

Is there any model number on the back?


73
Jeff

 

[NZ8N]

You could hook up the Vertical of a dual polarized antenna (Moonraker IV, PDL II, etc...) to the GR Plane port and the Horizontal to the Beam port. It does not have to be a Vertical Ground Plane on the upper half of the switch. Could also relabel it too, or even fancier, re-silkscreen it.

 

[guitar_199]

No sir. I have not opened it up..... but on the outside.... no.

Is there any model number on the back?


73
Jeff

 

[midnight special]

looks like a gc electronics copy,,, the gc models name for fame was even if swr was good using the tuner helped eliminate tvi,,, this was when radios did 4 watts and tvs still used outside antennas or rabbit ears,,,,the added switch was to have one less jumper in line,,,,

 

[barefootindian]

You could also try MIDLAND themselves. Their cb radios are very popular in the UK and also in ITALY.

 

[barefootindian]

guitar_199 the www address is midlandeurope.com but thats not a link to the address. They have a support section if you scroll down past the radio section. Hopefully you will be able to get any answers you seek from them.
Hope this helps

 

[guitar_199]

Thanks for that. I will look into it.

guitar_199 the www address is midlandeurope.com but thats not a link to the address. They have a support section if you scroll down past the radio section. Hopefully you will be able to get any answers you seek from them.
Hope this helps

 

[AudioShockwav]

Try

https://midlandusa.com/pages/support

Don't know if they will have anything on a piece that old but worth a try.
73
Jeff

 

[sunbulls]

IMO it’s a valuable project box because it’s metal. For starters I dislike rivets. Those would all be ground off and replaced with screws and star washers. I can’t say those cheap rockers that are seen in many CB antenna switches like that thrill me either. I can think of a few projects for that box, but I’m afraid most of them would be time consuming. For me, quality concerns regarding all things dealing with RF take precedence.