Radios and intercoms??

[Guest nunans]

There's always so much to learn with aircraft that's for sure,

 

I seem to be on a constant path of enlightenment with this flying hobby and at the moment it's the radio in my recenty purchased aircraft.

 

It's a BendixKing KY97a. Everything seems to work fine except the mics are "hot" all the time. ie any sound in the aircraft is constantly being fed back through the headphones.

 

There are pilot and copilot sockets in the cabin and all sound from both mics comes through both headsets all the time.

 

It makes it hard to hear the VHF over the top of all the noise and the only way i've found to shut it up is to pull my mic plug out of the socket but then I have to plug it back in again to make a call or talk to my passenger.

 

Is this normal? do I take it that these $2000 radios don't come with any type of VOX function on the mics and a separate intercom is required if you don't want the noise?

 

I did find some pots which i can get to through holes in the case (carrier squelch, noise squelch and sidetone) but had no luck with any of them.

 

I have so little experience with this that i'm not even sure if something is wrong with the unit or if it is supposed to have a separate intercom but I'm sure not putting up with it the way it is.

 

 

[rankamateur]

Sounds like you need to turn up the squelsh on the intercom, but I completely unfamiliar with this radio. Have you tried downloading the manual for it if none was supplied by the previous owner?

 

 

[Guest nunans]

Sounds like you need to turn up the squelsh on the intercom, but I completely unfamiliar with this radio. Have you tried downloading the manual for it if none was supplied by the previous owner?

I dont have a separate intercom maybe thats the problem but i thought there might be an intercom function in the radio. i need a really basic understanding of what the radio is supposed to do. maybe i'm trying to get a function to work (intercom with vox) which the radio doesnt have?

 

 

[Guest Maj Millard]

nunans, Go to the Sigtronics website. You can access installations diagrams for their sp400 series of intercom boxes used with all radios. They are very handy for reference. If you need an intercom box you won't do better than the Sigtronics one for the price. I have an ICom radio with Sigtronics intercom box in my Lightwing and intercom and radio operation is always excellent. I also have the standard LW wiring diagram for intercom/radio hook-up if you need it. alternatly Mark (Kyle Communications) may also be of help here...I believe the King ky97a is an older model but the King range is usually pretty good. It is possible the prev owner used a mobile intercom box which he may have kept ?.............................Cheers Maj...

 

 

[cscotthendry]

It might be worth a quick call to the previous owner to see what he did. Maybe it's just an adjustment. Maybe your headsets aren't compatible with the way the radio installation was done (ie the installation relies on noise cancelling mics and yours doesn't have that). If your installation doesn't have an intercom, was it taken out pre-sale?

 

 

[Guest nunans]

nunans, Go to the Sigtronics website. You can access installations diagrams for their sp400 series of intercom boxes used with all radios. They are very handy for reference. If you need an intercom box you won't do better than the Sigtronics one for the price. I have an ICom radio with Sigtronics intercom box in my Lightwing and intercom and radio operation is always excellent. I also have the standard LW wiring diagram for intercom/radio hook-up if you need it. alternatly Mark (Kyle Communications) may also be of help here...I believe the King ky97a is an older model but the King range is usually pretty good. It is possible the prev owner used a mobile intercom box which he may have kept ?.............................Cheers Maj...

thanks for the tip on sigtronics. if i put one in ill get the sigtronics unit.

 

 

[Guest nunans]

It might be worth a quick call to the previous owner to see what he did. Maybe it's just an adjustment. Maybe your headsets aren't compatible with the way the radio installation was done (ie the installation relies on noise cancelling mics and yours doesn't have that). If your installation doesn't have an intercom, was it taken out pre-sale?

Hi. i tried adjusting on the radio and it didnt make any difference. maybe the radio squelch adjustments are u.s. or maybe they just dont adjust the noise that i want them to. What do you mean by noise cancelling mics? is that vox built into the headset? never heard of it but i can say the previous owner definately used different headsets to mine

 

 

[Guest Maj Millard]

Nunans, if you know any aircraft avionics or radio people, they often have used ones for sale. I bought my SP400 used for only $100, and it's always worked perfect. The SP400 is actually a four place intercom but you only use the two-place function for ULs. They are a great unit and are one of the original designed intercom box copied by many others. The nice thing also is you can easily download all the wiring diagrams for what ever radio set-up you have. there is also a mod you do on the Lightwing plug jacks that also improves things. I have the factory diagram for this and it just involves soldering a resistor between two wires. It improves reception and quality of sound. If you want to PM me a mailing address I can dig it up and send it to you...Also if you follow the Sigtronics wiring diagrams you'll get good results.......................................Cheers Maj...

 

 

[billwoodmason]

Nunans, I have a bendix king radio in my 20 year old other Jab. It is standard for the mikes to be open all the time - bloody annoying. I have heard of people who install a switch to cut out the mikes when not in use but it would be inconvenient to have to switch the mikes on to transmit out or talk to pax. The best solution is to install an intercom.

 

 

[Guest nunans]

Yep I ended up installing a flightcom 403 seems to be working well now

 

 

[M61A1]

nunans, Go to the Sigtronics website. You can access installations diagrams for their sp400 series of intercom boxes used with all radios. They are very handy for reference. If you need an intercom box you won't do better than the Sigtronics one for the price. I have an ICom radio with Sigtronics intercom box in my Lightwing and intercom and radio operation is always excellent. I also have the standard LW wiring diagram for intercom/radio hook-up if you need it. alternatly Mark (Kyle Communications) may also be of help here...I believe the King ky97a is an older model but the King range is usually pretty good. It is possible the prev owner used a mobile intercom box which he may have kept ?.............................Cheers Maj...

I know this thread is a bit old, but maybe you be able to answer.....

I've having trouble getting my intercom sorted in the drifter, short story, just bought a Sigtronics SAS-440, after speaking directly with Sigtronics in the US, (they said it was overkill). Methinks " that's what I want", and buy one from from a person on the sunshine coast. I have not air tested it yet, but it seems rather quiet, about 1/2 as loud as my radio. The instructions detail using a resistor to balance the radio and intercom. I settled at 110 ohms, because it made my radio quieter than I wanted, but the headset volume seems to be barely at normal speech levels with the volume flat out. I'm using standard 300 ohm speakers fitted in helmets with DC electret mics, wired exactly as a DC headset, even with CEPs it sounds rather quiet, is this normal for a Sigtronics unit? Or should I be sending it back?

 

I can hear clearly on the ground, but it's quieter than the poxy portable intercom I took out, it it was barely audible in flight.

 

 

[Guest Maj Millard]

m61A1, I am not familiar with that particular intercom box but I Gather it is a further development of the previous SP400 intercom box that I have in the Lightwing. Mine has always been loud and clear with no volume issues. Obviously these intercoms have four place capability but you only use the two.

 

Did you download and follow the installation instructions from the Sigtronics website ?......what radio do you have ?........does it have an inbuilt intercom function ?..........if so have you disabled it to allow use of the intercom box ?....................Maj.....

 

 

[M61A1]

m61A1, I am not familiar with that particular intercom box but I Gather it is a further development of the previous SP400 intercom box that I have in the Lightwing. Mine has always been loud and clear with no volume issues. Obviously these intercoms have four place capability but you only use the two.Did you download and follow the installation instructions from the Sigtronics website ?......what radio do you have ?........does it have an inbuilt intercom function ?..........if so have you disabled it to allow use of the intercom box ?....................Maj.....

I am using a handheld type Icom A-15 with the internal mic off (settings on the radio), the SAS-440 is advertised as a direct upgrade from the SPA 400. Yep followed instructions, there was a bit about if the radio is loud and the intercom weak, to solder in a resistor between 100 and 300 ohms to get a balance between the two. I tried a 300 ohm initially, then a 220 , then settled on 110 ( 2 x 220 in parallel) , because as the intercom got louder (not much), my radio got quieter ( much). I was only asking because you had some experience, having a Sigtronics IC in use, and might know what is normal for them.

It all works but just seems a little quiet.