| Author |
Message |
    
Funtimebob
Intermediate Member
Username: Funtimebob
Post Number: 152
Registered: 5-2002
| | Posted on Friday, April 15, 2005 - 4:58 pm: | 
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just curious as to the number of add in parts available for radios.
I know there is a
"Channel Guard"
" Echo Board/rodger beep "
but what other types of add ins are there available for different radios (GENERIC) not radio specific to improve performance? |
Racer_x
Intermediate Member
Username: Racer_x
Post Number: 320
Registered: 2-2005
| | Posted on Friday, April 15, 2005 - 8:04 pm: |
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Speech processor. |
Road_warrior
Intermediate Member
Username: Road_warrior
Post Number: 489
Registered: 7-2004
| | Posted on Friday, April 15, 2005 - 9:17 pm: |
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Racer X,
Does a speech processor work good
on AM, SSB mode??? Never used one./
Probably use stock mic with that also???
JIM/ PA/ CEF 375 |
Racer_x
Intermediate Member
Username: Racer_x
Post Number: 324
Registered: 2-2005
| | Posted on Friday, April 15, 2005 - 9:35 pm: |
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An aftermarket type would work on all modes because it would be installed in the audio chain. In fact, some actually plug into the microphone jack of the radio, and you plug your microphone into the speech processor.
Some speech processors that are built into radios only work on SSB because they're actually built into the transmitter stages and take advantage of the circuits used to produce SSB.
You can use any kind of microphone with them as long as you adjust the output correctly. The kit that Lou Franklin sells has special construction details to deal with high impedance and power microphone output. |
Bluegrass
Intermediate Member
Username: Bluegrass
Post Number: 307
Registered: 12-2004
| | Posted on Saturday, April 16, 2005 - 5:27 am: |
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My base bleeds alot on nearby channels could a channel guard stop that? |
Mrbigshot
Member
Username: Mrbigshot
Post Number: 57
Registered: 2-2005
| | Posted on Saturday, April 16, 2005 - 11:18 am: |
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nope just if others are bleading on you. if you are bleadfing on there speakers at the base of the antenna make a coil about a foot in diamater 6 or so loops and zip tie it, that will make a choke and stop most of the rfi. for tvi use a grounded tvi low pass filter. also if you have a sloppy radio or a low antenna you will do that quite a bit. for the radio make shure your limiter isnt cut, and the low pass coil in the back isnt streatched to much. try to go at least 30 foot at the feed point for the antenna. i have noticed the antron 99's (and max 99's) or other 1/2 wave antenna cause an awful lot of tvi. ground planes seem to only make them worse. a good 5/8 is better but not much. |
Funtimebob
Intermediate Member
Username: Funtimebob
Post Number: 154
Registered: 5-2002
| | Posted on Saturday, April 16, 2005 - 12:01 pm: |
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"My base bleeds alot on nearby channels could a channel guard stop that"
Should tighten things up on your RX quite a bit from what I've heard. |
Bruce
Senior Member
Username: Bruce
Post Number: 2492
Registered: 9-2003
| | Posted on Saturday, April 16, 2005 - 4:23 pm: |
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Fulltime
If you ADD the channelguard to the radio and dont replace the exsisting filter it works wonders. |
Racer_x
Intermediate Member
Username: Racer_x
Post Number: 325
Registered: 2-2005
| | Posted on Saturday, April 16, 2005 - 7:25 pm: |
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Channel Guard filters increase adjacent channel rejection. If someone is operating on a nearby channel with a CLEAN radio (modulation limiter working and properly adjusted to no more than 100%) a Channel Guard will greatly reduce the effect their radio has on your receiver. Even if they are overmodulating slightly (which means that they are actually transmitting on their main frequency and the frequencies next to them) it will still help to reduce the effect their main signal has on your receiver, but you'll still have the scratchy sound of the additional sidebands caused by overmodulation.
Unfortunately cutting limiters is pretty common to make radios sound louder. There are even guys on this forum that proudly tout it as the best way to be heard.  The only way you can get rid of on frequency splatter is to use a DSP filter and that depends on how effective the filter's algorithms are. I have an inexpensive AF DSP that works okay, but doesn't get rid of stronger splatter.
You don't get bleedover on speakers, it's called Radio Frequency Interference or RFI. Strong signals induce a current on speaker wires causing the interference. The best way to avoid that is to use SSB which doesn't have a carrier, or to move the antenna away from the interfering device. A nice high antenna, a coax choke and/or a radial kit will help to keep RF from traveling down the coax and causing a high field strength at ground level which is necessary for such interference.
A low pass filter helps to keep harmonics down, but harmonics don't cause that kind of interference. They cause TeleVision Interference (TVI) which is a specific type of interference caused by CB's 2nd and 3rd harmonics interfering with TV channels 2 and 6. |
Bigbob
Senior Member
Username: Bigbob
Post Number: 1822
Registered: 12-2001
| | Posted on Saturday, April 16, 2005 - 9:00 pm: |
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There's also "front-end overload" which is your txer over loading the reciever of boomboxes,tv,stereo's,sound systems and the only way to stop that is move your antenna at least 300 feet from all recieving antennas or turn off your rig and never transmit again.I overload my sound system,but rfi affected my neighbors apliances,installed an mfj lowpass filter(this was before copper carried it's many fine quality filters)and no more problem with the neighbors,still overload the sound system but just told the wife to get over it.Bigbob |
Racer_x
Intermediate Member
Username: Racer_x
Post Number: 327
Registered: 2-2005
| | Posted on Saturday, April 16, 2005 - 10:15 pm: |
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Bigbob - How did the lowpass filter solve the RFI? It only attenuates the harmonics. Are you saying that the harmonics were stronger than your actual transmitted signal and caused the problem? When you installed the filter did you change anything else like grounding the coax or your radio? |
Goat373
Member
Username: Goat373
Post Number: 63
Registered: 3-2005
| | Posted on Saturday, November 05, 2005 - 11:39 pm: |
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the lowpass filter worked because it was the harmonics causing the problems with rfi, not his 27 meg signal, more than likely it was his 50 some odd meg signal causing the problems...get rid of the harmonics get rid of the problem, unless the rfi is acctually being caused on 27 megs, in which case you must take further action |
