It is currently Thu Aug 28, 2014 3:09 am

Contact Us | All times are UTC - 6 hours



Welcome
Welcome to sparkyscbshack

You are currently viewing our boards as a guest, which gives you limited access to view most discussions and access our other features. By joining our free community, you will have access to post topics, communicate privately with other members (PM), respond to polls, upload content, and access many other special features. In addition, registered members also see less advertisements. Registration is fast, simple, and absolutely free, so please, join our community today!





 Page 1 of 2 [ 16 posts ]  Go to page 1, 2  Next
Author Message
 Post subject: Improving Receive.... to Modify or Not to Modify
PostPosted: Tue Nov 02, 2010 1:27 am 

Joined: Thu Jul 08, 2010 6:43 am
Posts: 36
Location: Northern California
Anyone out there done a receive modification to their CB? I've seen them on Ebay and they seem to involve replacing some diodes and a transistor which supposedly improves the receive with a lower noise floor. Ok so who has any experience with this, positive or negative? Any other options for improving receive? Does Sparky's do receive improvements and is it the same as the kits? I use a Texas Ranger 969 and it's a good radio but I'm pretty new to Cb's and don't have a whole lot of experience with other radios that I can compare aginst my own to know where it stands. Anybody have a TR-969 or 966 before and know how the receive stacks up against other models? For all I know it's top notch already and I'd just be wasting my time and money. Any thoughts?



_________________
TR-969WX Dual 2sc1969 Finals
TS-250HDV Killer Bee
Wilson 5000
RK56 Mic
Offline
 Profile  
 
 Post subject: Re: Improving Receive.... to Modify or Not to Modify
PostPosted: Tue Nov 02, 2010 5:14 am 
User avatar

Joined: Mon Nov 16, 2009 10:23 am
Posts: 282
Location: Gloucester City, NJ
Yes, Sparky does receive MODS and I'm thinking there are various types for various radios. Give him a call and he can fill you in. I do know that one has to be somewhat careful when doing these. Too much receive risks damaging the radio if/when you encounter a strong station that is very close.



_________________
"... it's not what you take when you leave this world behind you, it's what you leave behind you when you go."
Offline
 Profile  
 
 Post subject: Re: Improving Receive.... to Modify or Not to Modify
PostPosted: Tue Nov 02, 2010 3:17 pm 

Joined: Fri Dec 25, 2009 9:55 pm
Posts: 130
I have done the 2SC2999 and Schottky diode Mod. on a Cobra 29 LTD and on a Uniden PC68XL and there is a difference. The receive is much quieter.


Offline
 Profile  
 
 Post subject: Re: Improving Receive.... to Modify or Not to Modify
PostPosted: Tue Nov 02, 2010 5:05 pm 

Joined: Mon Nov 16, 2009 8:52 am
Posts: 508
I have sold and installed several of the kits and have recorded the noise level before and after the instal and they do work. The receive mod that this_is_nascar is talking about is a wire jumper to an IC on some radios or a mod to a receive section transistor and those are the ones that can case damage if you are too close to a strong signal in some cases. The schottky diodes that are used in the mod are the heart of the mod and really quiet the radio compared to most radios that have the glass diodes because the do a better job of swiching faster and cut the noise out especially in the NB section of the radio. The transistor sometimes becomes degraded over time and needs to be replaced and or the new transistor is an upgrade from the stock one that came with your radios. Typical transistors that came with the radios are 2SC1674(very good) and 2SC27XX series in exports and the 2SC2999 Sanyo is an upgrade or NTE107 that some of the kits come with. Hope this helps.


Offline
 Profile  
 
 Post subject: Re: Improving Receive.... to Modify or Not to Modify
PostPosted: Tue Nov 02, 2010 7:43 pm 

Joined: Mon Nov 16, 2009 4:14 pm
Posts: 914
The first step would be to make sure a proper receive alignment was done when the radio was tuned. Most cb shops and home do it your selfers skip this step. After that as stated above, there are good mods to have done.


Offline
 Profile  
 
 Post subject: Re: Improving Receive.... to Modify or Not to Modify
PostPosted: Tue Nov 02, 2010 11:23 pm 

Joined: Thu Jul 08, 2010 6:43 am
Posts: 36
Location: Northern California
Sounds like the best thing to do would be to send it in and have it checked out before I do any tinkering. Get the alignment done and see where it stands then. Probably have a couple other things done while it's there. Thanks for all the input and keep the opinions coming if anyone has experience with the receive upgrade kits.



_________________
TR-969WX Dual 2sc1969 Finals
TS-250HDV Killer Bee
Wilson 5000
RK56 Mic
Offline
 Profile  
 
 Post subject: Re: Improving Receive.... to Modify or Not to Modify
PostPosted: Wed Nov 03, 2010 3:55 am 
User avatar

Joined: Mon Nov 16, 2009 5:33 am
Posts: 482
Location: Pinellas County Jail
If your radio uses the 2sc1674 rf transistor the 2sc2999 mod will gain you about one s unit. MEASURED on my home generator the receiver went from about .6 uv to .3 uv on SSB.
The replacement diodes again in some radios work very well.
Another mod I did to my grant is a channel guard filter it at +/- 2 channels makes several "S" units diffrence. It will not help if the other station is trashy but will if the other station is simply strong.


Offline
 Profile  
 
 Post subject: Re: Improving Receive.... to Modify or Not to Modify
PostPosted: Wed Nov 03, 2010 11:54 am 

Joined: Thu Dec 10, 2009 7:25 pm
Posts: 201
Terrster,
The radio you have has about the best receive you can get in a CB radio from the factory for use as a mobile, it has a huge amount of gain built into the front end, more than a Galaxy 959DX both these radios use the same board but the Ranger 696 has some changes to it in the front end that add gain. If you are trying to use this radio as a base it would hear well on very low noise days but would bring in two much noise on noisy days compared to a Galaxy 959DX. Most radio mods that work well are on the older radios like the Cobra 2000GTL and the Cobra 148GTLs. But the Schottky diodes trick works on most CBs and 10 meter radios to dropping the noise floor down some and give you a better signal to noise ratio. If you have checked your radio using an A/B switch and found it to be down from the other radio, sometimes an alinement is needed, Look for a the CB shop that has the proper equipment an know how to give a good alinement. A good antenna could be a game breaker an make a big differance on how far you will transmit and receive. I use a Wilson 5000 on a little SUV and talk 35+miles away to friends from my mobile most everyday if there is not skip to deal with on CH19 in my area, an have talked 75+miles a couple of times since I put a Galaxy98VHD in the RAV-4 about 3 months ago. :) .....................Oldtimer


Offline
 Profile  
 
 Post subject: Re: Improving Receive.... to Modify or Not to Modify
PostPosted: Wed Nov 03, 2010 12:14 pm 

Joined: Mon Nov 16, 2009 11:24 am
Posts: 219
The biggest advantage to the 2SC2999/Schottky diode swap is replacing the (cheap) components the factory uses in newer radios with better quality components that generate less noise in the receive circuit.



_________________
There you go man, keep as cool as you can
Face piles of trials with smiles
It riles them to believe that you perceive the web they weave
And keep on thinking free
~The Moody Blues

WR0220 Washington State 38LSB
CPI • Cobra • Icom • Yaesu
Offline
 Profile  
 
 Post subject: Re: Improving Receive.... to Modify or Not to Modify
PostPosted: Wed Nov 03, 2010 4:03 pm 

Joined: Thu Jul 08, 2010 6:43 am
Posts: 36
Location: Northern California
Thanks for some really useful information fellow forum members.

wa4ch it sounds like switching to the 2999 transistor is a good mod and thanks for the real world numbers from your doing the swap. Any thoughts about which diodes are the best to use? I've thought about that channel guard filter myself and it sounds like a good improvement especially if making the receive more sensitive so glad to hear another opinion on that too.

walterb it was great to hear some info about my radio. It sounds like I picked a winner on the receive, that's good to know. Maybe I'll just get it aligned as I got it off Ebay and it's probably about 10 years old, might be worthwhile to have it gone over. Furthest I've made contacts so far is about 20 miles in my 4Runner with a Wilson 5000 but I think I could do better.
35 miles sounds like something to shoot for. :)



_________________
TR-969WX Dual 2sc1969 Finals
TS-250HDV Killer Bee
Wilson 5000
RK56 Mic
Offline
 Profile  
 
Display posts from previous:  Sort by  
 Page 1 of 2 [ 16 posts ]  Go to page 1, 2  Next

Contact Us | All times are UTC - 6 hours


Who is online

Users browsing this forum: No registered users and 0 guests


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Search for:
Jump to:  

cron

suspicion-preferred