| Author |
Message |
    
Jameslarson
Junior Member
Username: Jameslarson
Post Number: 49
Registered: 4-2006
| | Posted on Sunday, April 16, 2006 - 8:28 pm: | 
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My 148 transmits 1/2 k below what it should be on SSB as per reports from other CB'ers. My clarifier is NOT unlocked. Usually, the receiving station has the clarifier at 9:00 just to tune me in. Any idea how to fix this inside the radio? Thanks. |
Kid_vicious
Senior Member
Username: Kid_vicious
Post Number: 1436
Registered: 9-2004
| | Posted on Sunday, April 16, 2006 - 9:42 pm: |
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first you need to make SURE that the person you are tuning to, is right on freq.
do not trust anyones CB radio.
find someone with a ham rig, that is relatively new, and have them sit right dead on freq.
you will talk into the mic while turning VR5 SLOWLY, and in very small increments, checking with the receiving station each time you turn it.
make sure the clarifier knob is right in the center when you do this.
matt |
Patzerozero
Senior Member
Username: Patzerozero
Post Number: 2721
Registered: 7-2004
| | Posted on Sunday, April 16, 2006 - 10:14 pm: |
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i WAS right on freq when he was talking to me, kid  & i compared it with 2 other radios |
Yankee
Senior Member
Username: Yankee
Post Number: 1141
Registered: 7-2003
| | Posted on Monday, April 17, 2006 - 1:09 am: |
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If it's the lower side band you're talking about. Center frequency for lower sideband is below AM center slot.
In today's times, it's hard to say who's on frequency and who's not. With a good share of radios having single or dual open and wide range clarifiers.
Over the years I've operated sideband, I've copied stations all up and down the range of my clarifier, some stations as far off frequency as a whole half of a channel, and the people you're talking to will swear they are on dead center frequency. The clarifier on my Grant XL is plus or minus 7 KHz. from center, to be able to track stations that are off a little bit.
The information posted before my post is correct. And it's also a good idea to have someone with a frequency counter on the receiving end while you're tuning your radio.
Carl |
Ck29
New member
Username: Ck29
Post Number: 6
Registered: 3-2006
| | Posted on Monday, April 17, 2006 - 7:15 am: |
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I would check it with a frequency counter first. also can you tune in other stations close to 12 O clock on lsb and usb if you can then it's possible that your TX off set may need to be
adjusted. Also if your not familiar with doing
this adjustment take it to someone who is.
good luck and I hope you you get it straitened out. CK29 Pat |
Hotwire
Senior Member
Username: Hotwire
Post Number: 1182
Registered: 1-2005
| | Posted on Monday, April 17, 2006 - 11:28 am: |
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Yeah take the radio to a good tech with a freq counter. In my opinion somebody griping over half a kc is nitpicking! Your radio or his radio may have been just turned on and not warmed up all the way. I would not worry about it. All voices are different and I doubt that I myself can detect somebody off half a kc. |
Hollowpoint445
Senior Member
Username: Hollowpoint445
Post Number: 1179
Registered: 6-2004
| | Posted on Monday, April 17, 2006 - 12:59 pm: |
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500Hz (1/2 a kHz) is quite a bit off frequency on SSB. It's probably enough that noone on frequency could understand what you're saying. I can tell when someone is off by as few a 10Hz, and it starts to get annoying when someone is off by 50Hz or more. On AM it probably wouldn't be noticeable.
I suggest you find someone with a receiver that is capable of tuning to and zero beating WWV at 10MHz. Once it's been zero beat to WWV, have them tune to your frequency and check your radio's frequency.
Frequency counters are okay to get a radio close, but WWV is the frequency standard the whole world uses for HF, and I use my HF rig to get my CBs on frequency because it's faster, easier, and I think more accurate. Unless your frequency counter has a TCXO and/or a crystal oven, AND has been recently calibrated with WWV or some other high accuracy frequency standard, I wouldn't trust it.
If your 148 is off frequency in all modes then it's a fairly easy fix, but if it's off in just one mode it's probably best to get the radio aligned. The TX frequency adjustment in 148s is VR5, and it adjusts the TX frequency if the radio hasn't had the clarifier modified to track on transmit. |
Jameslarson
Member
Username: Jameslarson
Post Number: 53
Registered: 4-2006
| | Posted on Monday, April 17, 2006 - 11:15 pm: |
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Well, update. It only happens in SSB. AM is dead on, but on SSB, my freq counter is indeed showing I am off. Can this be fixed by simply turning a VR inside, or will that affect AM as well at this point? Thanks. |
Kid_vicious
Senior Member
Username: Kid_vicious
Post Number: 1441
Registered: 9-2004
| | Posted on Tuesday, April 18, 2006 - 12:09 am: |
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pat,
quit messing with the new guy by telling him he's off freq.!
we all know you're just playing around!
matt |
Hollowpoint445
Senior Member
Username: Hollowpoint445
Post Number: 1180
Registered: 6-2004
| | Posted on Tuesday, April 18, 2006 - 10:20 am: |
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How are you checking the frequency on SSB with a frequency counter? |
Jameslarson
Member
Username: Jameslarson
Post Number: 56
Registered: 4-2006
| | Posted on Tuesday, April 18, 2006 - 12:19 pm: |
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It is the ranger one that is hardwired in. It can detect receive and transmit. FC390 is the model. |
Hotwire
Senior Member
Username: Hotwire
Post Number: 1191
Registered: 1-2005
| | Posted on Tuesday, April 18, 2006 - 1:10 pm: |
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Opps I was thinking kc's. So he would be off actually 5 kc's. Which is half a hertz. Someone correct me if I'm wrong.
My 148 was off 9kc from the factory on AM and SSB! After my tech alighned it it was still a little off and my tech claims his gear tunes and zero beats to WWV also. Not until I took it to another tech just to get it dead centered did I finally get it just right. James according to Pat you was OK. Trust Pat James, he would not lie plus he knows his stuff. On air I trust Pats word over anybody else I have contacted. |
Yankee
Senior Member
Username: Yankee
Post Number: 1144
Registered: 7-2003
| | Posted on Tuesday, April 18, 2006 - 1:58 pm: |
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What is the counter showing on sideband? Is the receive frequency not the same as transmit? If not VR-5 is the cure. Remembering that the sideband transmit frequency is most times below that of AM on the lower side band. |
Jameslarson
Member
Username: Jameslarson
Post Number: 59
Registered: 4-2006
| | Posted on Tuesday, April 18, 2006 - 4:40 pm: |
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Hotwire, It was Pat that had mentioned to me that I was off. I could tell because I un turn had to tune him in, and before tuning him in, I could hear how off he was becasue he had to tune to me. I think I may have re-alligned everything just now. We'll see. Right now I have it where it's dead center on transmit and receive on AM, LSB, and USB. So it would be say 27.4050 for AM transmit and receive, 27.4050 on LSB transmit and receive, and 27.4050 on USB both transmit and receive. took me a few hours, but that is what it is. Is this correct? In other words being dead center for all 3 modes in transmit and receive (without speaking into the mic of course and mic gain at zero). Thanks. |
Hollowpoint445
Senior Member
Username: Hollowpoint445
Post Number: 1181
Registered: 6-2004
| | Posted on Wednesday, April 19, 2006 - 9:04 am: |
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How did you manage to get all of the modes onto the same frequency? VR5 changes the transmit frequency of all modes, so just adjusting it wouldn't do anything to change the frequency difference among the modes. Did you adjust something other than VR5?
I really wouldn't trust that kind of frequency counter enough to do an alignment - it's just not accurate enough and it doesn't have adequate resolution. It can get you close, but close only counts in horse shoes, hand grenades, and thermonuclear warfare. I prefer to use a radio that can zero beat WWV as a frequency standard rather than a frequency counter.
Yankee - I believe that counter automatically compensates for the SSB offset, so there should be no difference in the reading mode to mode.
Hotwire - kc and kHz mean the same thing - 1000 cycles per second. Before the unit Hertz was adopted, everyone referred to frequency by cycles per second. |
Jameslarson
Member
Username: Jameslarson
Post Number: 61
Registered: 4-2006
| | Posted on Wednesday, April 19, 2006 - 10:29 am: |
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Yes, a combination of VR5 and the 3 individual tuning coils (You know, the ones that are in a small metal square box for each one, and from the top, you put a small plastic flat head screwdriver and turn) just to the right of it (1 for AM, 1 for LSB, and 1 for USB). |
Hotwire
Senior Member
Username: Hotwire
Post Number: 1195
Registered: 1-2005
| | Posted on Wednesday, April 19, 2006 - 11:53 am: |
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Ok Hollowpoint I see now, cool. Thank you sir
Oh James I see! I misread Pats post! I stand corrected. I uped my caffiene intake today so maybe I will be sharper. lol |
Hollowpoint445
Senior Member
Username: Hollowpoint445
Post Number: 1184
Registered: 6-2004
| | Posted on Thursday, April 20, 2006 - 11:56 am: |
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Kudos to you James! That's not an easy thing to do without the proper equipment. |
Kid_vicious
Senior Member
Username: Kid_vicious
Post Number: 1462
Registered: 9-2004
| | Posted on Thursday, April 20, 2006 - 7:10 pm: |
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he must've read my article! (just kidding!)
(breaks arm patting himself on the back)
matt |
Patzerozero
Senior Member
Username: Patzerozero
Post Number: 2732
Registered: 7-2004
| | Posted on Friday, April 21, 2006 - 6:33 pm: |
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if the days only had 36 hours in 'em, & there were 8 per week...glad to see it's back on freq. maybe we'll hear ya in there over the weekend. yup, it was 500Hz + or - to the low side on the receive of my ic735, ar3500 & S9. while they may not be perfect either, he was undecipherable against the other stations on freq, local & dx at the time. i could tune my rcv to him, to stay on xmit freq to the others, but, then the others were undecipherable to me. different ears hear differently, 100Hz can make a difference, any more is too far out.
hope your arms OK kid i know how it is when we get our heads stuck in the door  |
