I am sorry to be a pain in a$$ about stuff but I am not sure why but my uniden 76xl talks farther than my 148gtl malaysa that I just picked up off ebay. It is a mint 148 that has a peak and tune on it and has the extra channels but for me it sucks. I have called for a radio check on 19 and haven't heard anything but on my 76xl I can call and always pick someone up. What is gioing on? Also talking with a buddy tonight and I was on 19 am and for some reason he could hear me on 12 am like I was right next to him. I am new to CB in general and trying to learn as much as I can but this is buging the hell out of me. The 148 is supposed to be a better radio but the 76xl seems to me to be the better radio. I also can't get the 148 to tune in on ssb. Help!!! any comments are great.
-
You can now help support WorldwideDX when you shop on Amazon at no additional cost to you! Simply follow this Shop on Amazon link first and a portion of any purchase is sent to WorldwideDX to help with site costs.
148gtl question
- Thread starter jbo
- Start date
Your 148 is a fine radio jbo .....this is what one can exspect from Ebay from time to time )-: .....it sounds off frequancy and can use an alighnment or maybe even more ? ....your in luck !! it fires up transmits and receives !! .....it needs a good doctor jbo .......in this case I would say your 76XL would appear to be the better radio (-: (that's obvious in your case) Your 148 should be able to be fixed jbo and work the way it should........IM sorry for your problems dude .I've been there done that concerning Ebay ...I would like to think that your 148 could well be an easy fix , good luck to you.
Hi JBO,
The transmitter in each of those two radios should have nearly identical range. You mentioned "extras". Would "extra" channels be part of the picture?
Best clue you provide is that your buddy hears you just fine on the wrong channel. That means that it transmits okay. Just not on the channel you think.
This could be a side-effect of an "extra" channel setup gone wrong, or a simple failure of the channel selector, or maybe the wiring between it and the rest of the radio.
It will take basic test equipment to get to the heart of this problem. A meter to confirm that it's delivering the normal transmitter power, and a frequency counter to verify WHICH channel it's really on would be a good start.
If you don't have that stuff on hand, it's time to find someone who does.
73
The transmitter in each of those two radios should have nearly identical range. You mentioned "extras". Would "extra" channels be part of the picture?
Best clue you provide is that your buddy hears you just fine on the wrong channel. That means that it transmits okay. Just not on the channel you think.
This could be a side-effect of an "extra" channel setup gone wrong, or a simple failure of the channel selector, or maybe the wiring between it and the rest of the radio.
It will take basic test equipment to get to the heart of this problem. A meter to confirm that it's delivering the normal transmitter power, and a frequency counter to verify WHICH channel it's really on would be a good start.
If you don't have that stuff on hand, it's time to find someone who does.
73
Please tell me you did nto say that the transmitters in each radio would have identical range. Ok, I'll grant you that in the legal FCC world, thats true. In the peaked-and-tune world that real people live in, the 76 will totally STOMP the 148 just because of the stronger modulation circuit. Try looking at the modulation signal on a 'scope before it goes through the RF choke at the final. Look at the difference in level from the 148 to the 76. You'll find that the 76 is a good deal higher. the 148's max modulating voltage tops out around 13 volts or so, depending on the radio's supply voltage. The 76 will top out at well over 20 volts because of the transformer action. because of its regulator modulation, the 148's carrier supply voltage needs to be limited to about half of the radio's supply voltage. The 76 doesn't have that limitation. It sees the full 13 volts of the radio's supply, and that 13 volts goes through the secondary winding of the transformer. When modulating, the final and driver see a voltage that swings from the 13 volts key voltage to between 0 and close to 26 volts. BIG difference.
As for your buddy hearing you on 12 AM when you were on another channel, the others are probably right. Its liekly a channel mod gone wrong, and I wouldnt be surprised to find taht the SSB issue is part of that problem.
As for your buddy hearing you on 12 AM when you were on another channel, the others are probably right. Its liekly a channel mod gone wrong, and I wouldnt be surprised to find taht the SSB issue is part of that problem.
Hi DTB,
You're right on the money in the technical department about comparing two types of AM transmitter. The '76, or equivalent, will probably show one-and-a-half times the modulated PEP as the '148/GrantXL/LT-type SSB radio.
The SSB transmitter used in those radios can be "power-jumped" to creep past the 20-Watt PEP mark on AM, and the Cobra29/Uniden PC-76/78 will routinely hit the 30-Watt PEP mark with minimal tweaking.
Still, a proportion of one-and-a-half-to-one will result in NEARLY identical transmit range. Put the two of them on a coax switch, comparing with the same antenna. The 1.8 dB difference between them will show up around the width of the S-meter needle at the other end, and not much more.
They won't look all that much alike on a true PEP wattmeter at your end. A wattmeter scale will make them look pretty different. But it's a much smaller difference at the far end. Until the stronger radio of the two gets close to the noise level at the far end, they'll both be heard.
I did say "nearly".
They will sound different, but I'll leave that part to somebody else to decide which one sounds "better".
73
You're right on the money in the technical department about comparing two types of AM transmitter. The '76, or equivalent, will probably show one-and-a-half times the modulated PEP as the '148/GrantXL/LT-type SSB radio.
The SSB transmitter used in those radios can be "power-jumped" to creep past the 20-Watt PEP mark on AM, and the Cobra29/Uniden PC-76/78 will routinely hit the 30-Watt PEP mark with minimal tweaking.
Still, a proportion of one-and-a-half-to-one will result in NEARLY identical transmit range. Put the two of them on a coax switch, comparing with the same antenna. The 1.8 dB difference between them will show up around the width of the S-meter needle at the other end, and not much more.
They won't look all that much alike on a true PEP wattmeter at your end. A wattmeter scale will make them look pretty different. But it's a much smaller difference at the far end. Until the stronger radio of the two gets close to the noise level at the far end, they'll both be heard.
I did say "nearly".
They will sound different, but I'll leave that part to somebody else to decide which one sounds "better".
73
- No one is chatting at the moment.
