[K2CC] New Equipment

John Robinson johnwesleyrobinson at gmail.com
Tue Nov 18 19:37:38 EST 2014

Well here is some gory details on how to implement such a phase reversal circuit from one of the audio sites I frequently visit. http://sound.westhost.com/project107.htm . I do not see transformers working in a common ground scheme as the signal needs to be physically inverted in such a scheme as you would be driving the signal to  the ground of the other speaker most likely resulting in undesired results.

I may experiment one day with a variable phase circuit and see if it yields anything beyond a echo... It will probably be based on the Marantz vari-matrix circuit. This is what happens when you dabble in audio circuits for too long and vintage Marantz gear.


> On Nov 18, 2014, at 4:17 PM, Greg Zenger <n2gz at gregzenger.com> wrote:
> You know what John, I thought about the whole roll-your-own breakout box idea for phase reversal switch and almost recommended such a thing in my previous email.  However most (maybe even all) headphones share a ground between the left and right channels which means such a breakout box approach would need audio transformers on both the input and output to re-derive the grounds prior to transmission over the common ground conductor in the headphone cable.
> Greg N2GZ
>> On Nov 18, 2014 3:03 PM, "John Robinson" <johnwesleyrobinson at gmail.com> wrote:
>> I also highly recommend the linemaster clipper foot switch. They are well built, cast metal and made in the USA here in Woodstock, CT. I actually have one currently in front of me on a piece of medical equipment at work.
>> I modified a pair of headphones with a in/out of phase switch as Greg had mentioned. The pair I modified is a yamaha CM500 which are about 60$. They are a pretty decent pair and have plenty of room inside for the switch if you wish to add the feature. They also do not sound bad either and receive decent reviews. I suppose you could also roll a switch box which the headphones plug into and make any attached headphones in/out of phase without any physical mods to the headset.
>> For mic jack adapters i have picked up a couple W2ENY made adapters off ebay as I was often too lazy to roll my own. They work well and shipped from NY and support an ham in NY. Just a throwing it out there for another source I have used.
>> -John
>> > On Nov 17, 2014, at 10:53 PM, Ethan Miller - millere <millere at clarkson.edu> wrote:
>> >
>> > The boom mic is in addition to the heil proset we already have. Good things to note on the other equipment, thanks!
>> >
>> > - Ethan
>> >
>> >> On Nov 17, 2014, at 22:45, Greg Zenger <n2gz at gregzenger.com> wrote:
>> >>
>> >> I'll toss in my two cents here, if you dont mind.
>> >>
>> >> The PR781 is a great microphone... however consider the environment of the
>> >> station.. Im not sure of how things are setup now in the new station, but
>> >> back in the late 2000's there was often a lot of 'spectators' hanging
>> >> around the radio during contests. And by hanging around, I mean goofing off
>> >> and being social. A big boom mike like that is likely to pickup alot of
>> >> background noise. Not good.
>> >>
>> >> I prefer to operate with a headset with a boom mic.  A headset helps put
>> >> the sound inside your head; you can hear things that you cant hear
>> >> otherwise when you are diggin' out that weak signal under all that splatter
>> >> from the guy transmitting a few kc above or below. a headset with a phase
>> >> reversal switch is nice. I use the Heil Pro Set Elite 6. Though keep in
>> >> mind Its possible to do phase reversal on any headphones if get creative
>> >> like K1JR did and build one into your favorite headphone.. A double pole
>> >> double through switch installed to reverse the polarity of one of the
>> >> speakers is all it takes.  The PowerSDR software might give an option to do
>> >> it in software... I don't remember.
>> >>
>> >> The club should definitely have an adapter like the HLS-AD-1-YM.... I bet
>> >> you could build one using parts found around the shack.
>> >>
>> >> This year we used both an external speaker for spectators to listen, and
>> >> had the Heil Pro Set Elite 6 for the operator... it worked well.  Going
>> >> forward, I think it might be nice to have a multi channel headphone amp to
>> >> allow additional headphones to be plugged in with independent volume
>> >> control.
>> >>
>> >> I do not recommend the Heil foot switch... I bought one once and it felt
>> >> cheap and I just didnt like it... Save up and get a a Clipper... (model
>> >> 632-SC3)  Here is a decent deal.... though ive seen them cheaper at
>> >> hamfests:  http://ebay.to/1AaqcM3  Its cheaper than the Heil, and anyone
>> >> can figure out how to wire it in.  Put an RCA connector on it and plug it
>> >> into the back of the F3K.
>> >>
>> >> Best of luck and 73
>> >>
>> >> Greg N2GZ
>> >>
>> >>
>> >>
>> >>
>> >> On Mon, Nov 17, 2014 at 9:03 PM, James P. Dapp - dappjp <dappjp at clarkson.edu
>> >>> wrote:
>> >>
>> >>> Hey all, some of our equipment broke this weekend and we are looking to
>> >>> buy some new gear. As for the microphone, here are a few to consider:
>> >>>
>> >>> http://cart.flexradio.com/Heil-PR781-Balanced-Microphone_p_21.html
>> >>> http://cart.flexradio.com/Heil-HB-1-Microphone-Boom_p_837.html
>> >>> http://cart.flexradio.com/Heil-FS-2-Dual-Foot-Switch_p_836.html
>> >>> http://www.dxengineering.com/parts/hls-ad-1-ym
>> >>>
>> >>>
>> >>> _______________________________________________
>> >>> K2CC mailing list
>> >>> K2CC at lists.clarkson.edu
>> >>> http://lists.clarkson.edu/mailman/listinfo/k2cc
>> >> _______________________________________________
>> >> K2CC mailing list
>> >> K2CC at lists.clarkson.edu
>> >> http://lists.clarkson.edu/mailman/listinfo/k2cc
>> > _______________________________________________
>> > K2CC mailing list
>> > K2CC at lists.clarkson.edu
>> > http://lists.clarkson.edu/mailman/listinfo/k2cc

More information about the K2CC mailing list