| Author |
Message |
    
619
| | Posted on Saturday, June 22, 2002 - 9:45 pm: | 
|
how does the new 148st rate to the texas ranger 296 thanks for your response |
ss8541
| | Posted on Sunday, June 23, 2002 - 10:36 am: |
|
the 148st's aren't that great. the foil traces might as well just been painted on they are so thin. with that comes 'floating' rf problems since there is no true rf gnd. the 9v reg shifts voltage with modulation. this causes the vco's freq to shift with mod also. in some radios i have seen the shift has been over 100hz(this is at max ssb power the radio can produce, about 25wpep). this isn't noticeable in am, but is very noticeable in ssb. the ssb operators who have these complain that no one can clarify them. this is because of this shifting of vco freq with mod. i have spent much time trying to force the floating rf away from the 9v reg. i've tried filtering, chokes, combinations of the two, and the only thing that really worked was adding a .1-.01 cap from the regs gnd to the chassis gnd of radio. it seems to help break up an rf gnd loop that is throwing the sampling element or Vref off in the 7809 reg. this along with reducing radios ssb output to about 18wpep, lessens the freq shifts to the point that is not noticeable on the rxing end.
basically the whole radio is one piece of floating rf when radio is keyed. you can key a 1w carrier and go to almost any point on the radio(including gnd) and read your tx freq on a freq counter through a 10x probe(this isn't for all, but most). with this there is no telling what other problems you may run into. and add an amp to the equation, and you're really asking for trouble.
the 296 is a carbon copy of the old 148gtl. very good radio in my opinion. you really can't compare the 2. one works well, the other does not. |
Copperfan
| | Posted on Sunday, June 23, 2002 - 12:28 pm: |
|
What about the Ranger 696F |
619
| | Posted on Sunday, June 23, 2002 - 1:53 pm: |
|
thanks for your input, i will stay away from the 148st. i have had a galaxy 949 and a tr296 but the best radio a once own was the old royce 639 it had the cleanest receive i have heard. 73's |
Biged
| | Posted on Tuesday, June 25, 2002 - 8:57 am: |
|
ss8541,
That is the best explanation I have heard so far about the new cobras. I have always wondered why they were considered inferior compaired to the older ones...Eddie |
|
