Author |
Message |
Therealporkchop
Intermediate Member Username: Therealporkchop
Post Number: 127 Registered: 11-2002
| Posted on Thursday, February 03, 2005 - 11:32 pm: |
|
I have a Galaxy 77HML. I've done the receive mod to it where you lift the cathode end of D7 and install the 1.5k resistor. You can here an increase and units close to you that are very strong will distort the radio. I've disconnected the roger beep and use this switch to control the receive mod. My question is are there any other modifications that can be done to the receive of these (or any Galaxy) radios to improve it? Also does anyone know how to increase the volume of the audio, like changing a resistor to increase the gain from the mic? |
Bruce
Senior Member Username: Bruce
Post Number: 2174 Registered: 9-2003
| Posted on Friday, February 04, 2005 - 7:31 am: |
|
humm does that radio use a 2sc1674 rf stage? if so replace it with a 2sc2999. |
Therealporkchop
Intermediate Member Username: Therealporkchop
Post Number: 129 Registered: 11-2002
| Posted on Friday, February 04, 2005 - 3:59 pm: |
|
Bruce, I don't know. How could I find that out? I don't have a schematic for this radio. |
Barracuda
Intermediate Member Username: Barracuda
Post Number: 282 Registered: 3-2003
| Posted on Friday, February 04, 2005 - 5:20 pm: |
|
Bruce, What benefit does the 2sc299 have over the 2sc1674? I noticed on the Galaxy radios that they do use the 1674s. Also, I remember hearing somebody suggest a repacement for the RF amp in a Galaxy but cautioned against it because of stability problems ( the new rf amp would break into oscillation). do you know if that might have been the 2999? 73
|
Patzerozero
Intermediate Member Username: Patzerozero
Post Number: 411 Registered: 7-2004
| Posted on Friday, February 04, 2005 - 6:14 pm: |
|
i solved the galaxy receive problems i always had, porkchop! i bought an ar3500, grant xl, grant lt, delta force, S9...just messin' wit ya! have a disabled dx33, i found 2 1674's in it, not sure which is the right one, though. bottom cover off, back of radio towards you, the 1st is lower right corner about 1 & 1/2 " up & in, between round coil L6 & can L7. the 2nd, is about 1 & 1/2 " lower left of ch selector board between xtal & VR5. not sure how that will help you, but it's the best i could do!!! maybe bruce will let us all in on the secret as to which one, then he won't be the one with best receiving cb anymore! |
Barracuda
Intermediate Member Username: Barracuda
Post Number: 283 Registered: 3-2003
| Posted on Friday, February 04, 2005 - 6:16 pm: |
|
Bruce, I assume that your answer is going to be that the 2sc2999 has a lower noise figure. I don't mean to sound flippant, but how important is that in an environment where there is a contant received noise level of S3+? I have done some experiments with the same antenna switched between my galaxy959 and my FT-857d (recieve only!). Both provide similar results on 38lsb (or anywhere else on 11m) in terms of received background noise. I know for sure that the FT-857d has a much better front-end, so I'm assuming that all that noise is received. I could certainly understand having an rf amp with the lowest possible noise figure in extremely quite band conditions where you would not want the RF amp noise to dominate the audio you put out the speaker. I just haven't found anyplace on the 11M band where that would be a problem (yet, I'm still lookin') 73 |
Barracuda
Intermediate Member Username: Barracuda
Post Number: 285 Registered: 3-2003
| Posted on Friday, February 04, 2005 - 6:41 pm: |
|
Patzerozero, the 1674 (TR17) to the left of L6 is the rf amp on the 33. |
Therealporkchop
Intermediate Member Username: Therealporkchop
Post Number: 130 Registered: 11-2002
| Posted on Friday, February 04, 2005 - 11:29 pm: |
|
I knew if anyone would mess with me, it would be you Pat. Thanks for the info though, I'll have to check into that. Barracuda, speaking of the FT-857d, how do you like that radio? I am thinking of getting one of those so I can make some use of my ticket. I know it wouldn't be legal, but I'd like to unlock it so I could use it on 11 meters, maybe run it in my truck too. There has to be something you can do to the Galaxy radios to improve the receive quality. Just as I am sure there are things you can do to improve the tone and loudness of the mic gain. |
Bruce
Senior Member Username: Bruce
Post Number: 2176 Registered: 9-2003
| Posted on Saturday, February 05, 2005 - 12:26 am: |
|
I FOUND THIS Radio is a grant LT 2sc1674 noisefloor ( LOS ) .2 uv 2sc2999 .1uv now when things are VERY quite you can still hear background noise with the 2sc2999 and you cant with the 2sc1674 ....... |
Barracuda
Intermediate Member Username: Barracuda
Post Number: 287 Registered: 3-2003
| Posted on Saturday, February 05, 2005 - 11:32 am: |
|
Therealporkchop, To be honest, I haven't used it all that much yet. I only bought it recently and have not yet set it up in the home shack. I'm waiting to buy a PS, tuner and antenna for it at a local hamfest at the end of the month. I've only been using it occasionaly mobile. But, from the little bit I have used it I do like it very much. I have found that the controls are logically laid out (for me) and the menus are fairly easy to use. I would not want to have to play with them too much while driving, but as a base it would not be a problem. One thing I did find when I was using it mobile on 2m was that unless I locked the controls the tuning knob would rotate a small bit due to vibration and put me off frequency. No big deal, just a button press and on 2m I don't need to fiddel with it anyway. Have fun with it if you get one. 73 |
Therealporkchop
Intermediate Member Username: Therealporkchop
Post Number: 132 Registered: 11-2002
| Posted on Saturday, February 05, 2005 - 1:46 pm: |
|
Bruce, so what are you saying? I understand that the 2999 will give a little background noise, is that white noise or hum or what? Or are you saying that it receives better, and that is why you will hear the noise? Is that a part I can pick up at the shack or will need to order from my regular source? Do you think there will be a problem with my front end being overdriven like with the mod I have now? Do you think I'll need to remove what I've done now for this to work? |
Therealporkchop
Intermediate Member Username: Therealporkchop
Post Number: 133 Registered: 11-2002
| Posted on Saturday, February 05, 2005 - 1:49 pm: |
|
Barracuda, as for the 857, I will get one. No time soon, but I will get one. Long before I thought of even getting the ticket, I saw this radio I thought it was cool. If I'd have known I could have used it on 11 meters, I probably would have got one anyway. I don't get on the air a lot anyway, and I hardly ever talk on any amatuer band in my truck anyway. I run a dumptruck and there is too much going on, and I don't have time. At home I'm using my brother-in-laws HT and a 3 element beam I built myself. With only 6 watts from the HT I can hit the repeater about 50 miles or so away and get them loud and clear. I figure that isn't bad for a 2.50 antenna I built out of PVC and old fence wire. |
Patzerozero
Intermediate Member Username: Patzerozero
Post Number: 418 Registered: 7-2004
| Posted on Sunday, February 06, 2005 - 6:41 pm: |
|
i'm in the same boat you are, TRPC-have tech, but NO radio at all! been looking for a ft897 or 897d for base, know somebody who has 1, sounds good ssb & fm, though typical amateur AM sound, & it too is modifiable for 11. & they're not all that much $, aes had brand new 897 (non-d) for 699. also looking for ic706mkIIg modifiable for 11 also, would go good in my mobile & i know someone with 1 also, he does use it AM on 11 & it sounds real good! |