Lets fix this CRT SS6900N. CB RADIO in the UK

All thanks goes to Gary for his help in this adjustment of the CRT SS 6900N CB RADIO.

[@CB-RADIO-UK]

Had SSB contacts on the 7am 305 net and all sounding good so far.

[@GLICKTON]

"DAVES STILL GOING ON THERE" turns the volume down to carry on with his vid, hilarious :))

[@user-bd4zb8jk6w]

I'm glad you fixed it in the end. It sounds good. 😊😊😊

[@errolharriott2889]

FITS, great video, thank you and i will bare this in mind moving forward,

[@scotthamilton7856]

"Stuck it to the end"! Very interesting as always. My 6900N arrives tomorrow but i wont be taking the lid off lol!!

[@CB-RADIO-UK]

Thanks for sticking with it. No dont touch your radio LOL.

[@RobR386]

I normally use a sharpie and draw a line on potentiometer or slugs before I adjust them, so I can return them back to default settings if it doesn't work, take a picture too before adjusting.

[@CB-RADIO-UK]

Good advice Rob. Cheers

[@glynnhm0lsg308]

Good advice about the pictures

[@oldmanandguitar]

The fm deviation, am and ssb modulation are set to the standard mic in factory, more powerful mics often cause problems.

[@cmj20002]

Some radios don't do well with power mic's, so I would just run a standard microphone. Also when you adjust any pot in the radio use a ceramic screwdriver and be really careful. Those smd pots are very fragile and can come apart. Just don't use a power mic and all will be good.

[@CB-RADIO-UK]

Your right. I went back to a non powered mic in the end. Good call on the screwdriver.

[@chriscutting5773]

I agree i use plastic tuning tools designed for the job stops you shorting anything out better safe than sorry

[@MM0IMC]

Sounds like audio feedback due to the use of a power mic. The standard mic is more than adequate. Modern radios don't need power mics anymore. Could have been RF feedback to.

[@rpcomms1]

Hi Fred,something not really talked about much ,switch modes psu -are commonly DC isolated,the DC ground should not come in contact with Frame ground or real earth. They often go noisy and cause RFI and other problems. SS-3900 uses isolated radio chassis,so DC ground neg is not connected to the radios chassis\S0-239 connector SS-6900 uses common radio chassis,so DC ground neg is connected to the radios chassis\S0-239 connector So when you connect your coax antenna up to antenna on SS-6900,the outer braid sits at DC neg potential (measure it on ohms with DVM) when other end is plugged into antenna\bracket,the antenna must be isolated (ive used Breadboards PTFE) ,reason being the minute mast is connected to poles\mast it will be at real earth potential and that SMP will see a near short circuit creating a problem. DC isolated switch modes should never have the DC neg tied to earth ,big no no Unfortunately its not a well understood subject The radio SS-6900 and antenna system can form that bridge if your mast is at earth potential and your coax (via so-239 socket is sitting at DC neg) to create this problem. I had the reverse problem on SS3900 using fibre mast and SMP, i had to common ground the DC neg to radio chassis internally on the PCB via a solder strap. It fixed my prob on ssb and no more nasty modulation. And avoided the above SMP rule of thumb. Another little talked Issues on some smp,is you can get AC volts floating on DC outputs! Some SMP's PSU do not fit 2 special capacitors to filter out the AC leakage. You can easyily check this using a DVM set to AC volts. Put one end of probe on DC neg,other to chassis of SMP PSU read AC voltage,some measure as high as 100VAC do same test from DC pos to frame ground,should be same AC volts value. If its more than say 1VAC to 100VAC the fix is use 680nF 1KV DC 310AC X1 capacitors fit one on DC pos terminal nad other end to Earth\Frame ground of psu metal chassis enclosure of PSU do the same with another capacitor of same value\type on DC neg terminal and other end of cap to frame\earth ground of chassis enclosure of PSU. Redo you AC Volts test and Bingo all you AC volts floating on DC outputs gone! should be less than 0.6V AC floating on pos or neg DC terminal now,problem solved. and less hum\RFI issues too. Hope that helps woth a check on your SMP PSU,Ive fixed loads of SMPs and used this rule of thumb with SMP and radio's and antenna grounding systems. I get no issues now,most of my antenna masts are isolated now with fibre pole section where antenna mounts on and connects to antenna metal mast. The metal mast sections is bonded to EARTH via copper rod,but insulated section of fibre pole prevents the rule of thumb,cant short DC neg via coax to antenna to frame ground when using smp. Thats why smp go RFI noisy,they are not supposed to be common grounded in first place! lots of modern text books refer to common ground psu,this is not the case with SMP's PSU mostly all now are DC isolated like this. I also discovered some modern Linear DC isolated types too,applied the AC leakage caps and again avoid the short circuit loop via ur radios coax\grounding system. took me 2 years to figure that headache out Fred and a lot of hair-loss on a Industrial project! Have a go,scope the DC output and use a wire link from DC neg to PSU earth,ull see a ton of crap appear on Scope and Harmonics Also use a good quality 2 stage shield AC line filter on SMP PSU makes a heck of a difference to stop crappy noise going out and coming into your SMP! Hope that helps others and you Fred As for SS-6900 best way is injecting two tests tones at about 50mV RMS level into mic socket on SSB,then adjust ALC control for correct spec power quote in service manual. A rf sniffer connected to radio and a X,Y ports scope will show SSB wave form clearly. All the best Rob 73's

[@26DR715]

Hi Fred, I had the same problem with the same rig and power mic, even adjusting the levels down would work on FM but SSB was a waste of time. Ending up changing the power mic for a ham international power mic with no problems, glad you seem to have sorted it though.

[@CB-RADIO-UK]

Good to hear you got it sorted.

[@clarkspiemuncher24]

hello steven i am just coming into cb radio and getting a tcb-900 although already thinking i should have just jumped straight in and bought a ss 6900 so wondering what the ham international power mic is you mention and if you have information on where to get one and was it used on factory slandered ss 6900 or did you have to tweak radio to make mic work properly ?

[@roberthicks6697]

i have the same mic on the same radio , no issues. one point is make sure the thumb screw on the back of the mic is not grounding on the pcb, a simple washer to space the screw out a bit works.

[@CB-RADIO-UK]

Thats a very good tip on the 532. Poor design on that screw which causes a lot of issues.

[@damiendavies4248]

hi I've had good reports on fm and usb on my 6900n on the standard Mike I've got mine set to 40 on the function button icg working well ☺. good video m8 chris 13 ct171

[@stuartclark5191]

Had this distortion problem fred,solved it by turning off the talkback.

[@GeorgeEI7KO]

Good job Fred

[@CB-RADIO-UK]

Thanks George.

[@RonanKearney1]

hey Fred. Did you end up turning the watts power up again on the rig? Seems a shame to have extra power but not able to use it, i'm guessing turning the gain down in the settings was the answer. Thanks . I'll be up and running soon 26CT 1979. 73's

[@CB-RADIO-UK]

No i kept the power low at around 20 watts. The radio seemed happy at that level. It can be a push but i got some good DX on the 6900 today.

[@26fb384]

Big opening from north England to you guys down there. U wanna give it a go right now???

[@mcvicer]

Fred you are a man of mystery I hope one day to see your face lmao

[@CB-RADIO-UK]

;-) it appears in the odd reflection if you look careful

[@CT1JRZ]

Nice

[@delboyonline]

Probably RF being picked up on the mic lead. Try a clip on ferrite at the rig end. As you know you don't wire pin 4 on these radios as it carries voltage for the buttons on the original mic and the unconnected wire can sometimes pick up stray RF.

[@CB-RADIO-UK]

Thanks Del. Seems to be working ok now ive turned everything down.

[@robertdickson6317]

Del boy bang on its rf coming down the mic lead Fred its a cheap power mic the lead not well screened ferrite would hopefully address the problem on higher power the fact you had to lower power to improve things to me prove rf is the issue its normaly always the simple things first to check its quite a common mistake to fear its something more involved we have all done it at one time or another

[@CB-RADIO-UK]

Thanks Rob. Ive got a ferrite ring somewhere. I am going to replace all the RG 58 with 213 as ive started picking up my audio on headphones.

[@deano3258]

A very interesting video as I have just purchased the same mic and running the same radio. So far so good with no issues. My mic gain setting is on 30.

[@craigduncan8121]

Hi Fred. I've bought one of these radios and have had the same problem with AM and SSB. It seems to be an RF problem that earthing the radio and antenna helps with. I noticed when touching the radio that the noise from the mic lowered in volume. I remember doing exactly that way back in the 80s with another rig and power mic, it used to be a common problem. Stick an earth spike into the garden and ground everything, see how you go. Other than that small problem I've ben really enjoying the radio. It does produce a lot of heat around the power plug though, Has anyone noticed the same heat build up? Seemingly it's normal for these radios?

[@CB-RADIO-UK]

Hi Craig. Thanks for the info. I get heat build up near the mic plug on mine but nothing like the 9900

[@craigduncan8121]

@@CB-RADIO-UK Hi again Fred. Yes it's the CRT SS 6900N I use and it gets very warm up around the power socket and the antenna plug. No heat around the Mic socket on mine. I placed a PC fan behind it to direct air flow over the heat sink and rear case., it's worked wonders, heat is way down. It's wired into the power pack on the extra power output so goes off with the rig. Also I just did an experiment with the rig on am and sideband you might be interested in. I turned down the mic gain on the radio, then maxed out my hand held power mic to recreate the mic squeel, then slowly turned the mic gain on the radio down untill it dissapeared. It's getting good punchy audio but no squuel now on the hand held mics, mo old sadelta and even on an old Turner Expander. Although Turner sounds completely different on this radio to any other radio i've used it on. Anyway, sorry for the long rant, it's good to experiment and pass on info :)

[@oldmanandguitar]

Is the original mic electret? You can't wire the power that goes to electret mic to a dynamic/power mic.

[@CB-RADIO-UK]

Here is how Knights wired it. kzbin.info/www/bejne/qaWsh6CqasljgqM

[@norrlins]

Hi Fred . Great videos. I run a6900n , is there any way to disable the hi swr cut out. Its so annoying

[@CB-RADIO-UK]

Hi. Yes look for "tsr" in the menu and turn it off.

[@norrlins]

@@CB-RADIO-UK many thanks Fred.

[@ruimiranda2453]

yes but can get from England to contact Brazil or South America for example I stopped communicating on the radio for 12 years approximately but I have 160 and a few devisions confirmed but I will try again will see how it will be friend thanks for your attention good dx

[@petewright431]

where can I send the radio to get the power output on SSB turned down to about 15 w appreciate your advice

[@CB-RADIO-UK]

Could you not just use the TX power pot ?

[@petewright431]

Fred in the Shed not confident enuff to identify it or how much to turn it, dont want to damage a new radio but appreciate your response 😊

[@Reverend-Rodger]

Has somebody had their fingers in the back and cranked the alc right up?

[@CB-RADIO-UK]

Yes it had been pushed a little hard.

[@hermanvesper32]

Can you help me? On lsb the sound is very poor. HOW can i make this louder?

[@CB-RADIO-UK]

Hi. Sorry iam not the person to ask as i perform very little radio repairs.

[@greyhound0z]

Gary sounds like he's from up my way in Durham...what's his channel??

[@CB-RADIO-UK]

HI Gary does have a YT channel. Gary g1fsh. Its dormant though.

[@shizzle666440]

Hi Fred, i need to take off the front panel to fix my 6900 but I've run into a problem. The nuts on the potentiometers looks like lock nuts any idea what tool i need to undo them.

[@CB-RADIO-UK]

Box spanner. Cheap on Amazon. Like i did in this video. kzbin.info/www/bejne/b3XOYohqgM6nfc0

[@keithrobinson3532]

Fred could you let me know an inexpensive CB repairers. My SS 6900N blew up. And my t 800 blew up

[@CB-RADIO-UK]

Hi Keith. Rig doctors are like rocking horse poo these days. Very little repaired.

[@keithrobinson3532]

You just can't under estimate the necessity of using a SWR on your CB and Antenna. I found out the nasty hard way. Looks like I've got to dump my 5 week old SS 6900N I bought from Kamsat for £189 and my T 800 Thunderpole for £62. My learnt advice is GET YOUR Radio and Antenna SWRd

[@keithrobinson3532]

Anyone need a T 800 and SS 6900N for spares or repairs??

[@PaulMoorhousehankooks]

How do I get 27.555 MHz on my new crt rig ss6900n

[@CB-RADIO-UK]

It should be programed into one of the bands A-E etc.

[@ruimiranda2453]

yes but tell me if this radio is really good I was operator many years my radio station was 75 wd 002 I'm going back to the active soon I know that the wd group is over I should make a card of my own custom qso until soon colleague good qso ps. already reports to me how the propagation is

[@CB-RADIO-UK]

Propagation is very low this year. There are pockets of Eskip around but its going to be a while to things pick up and peak around 2025.

[@ruimiranda2453]

You have to adjust on the clarifaer.when you have to receive a transmission

[@CB-RADIO-UK]

Darn i knew i must have been doing something wrong

[@superhappygeorge3761]

How far are you and recipiant from each other?

[@CB-RADIO-UK]

Around 7 miles.

[@mrmike1096]

So which 1s for power ?

[@CB-RADIO-UK]

Cannot rem off hand. I did use it though as i reduced it.

[@ruimiranda2453]

do you know who can provide me with a new Syrian antenna 827 I think you do not have any website that can guide me I have to find more and negative

[@CB-RADIO-UK]

Not purchased one myself but good suppliers on ebay

[@CB-RADIO-UK]

www.ebay.co.uk/itm/Sirio-827-Base-Station-Antenna/182338368901?hash=item2a7436b585:g:49sAAOSwySlaHA7D

[@looneytune-upelectronicsll2241]

rui miranda have you ever heard of an antenna called " predator 10K "? I sale those and. I am thinking of building and getting a Patton for my own design for an antenna. antenna.

[@glynnhm0lsg308]

Made me laugh that after my alien hands comments

[@CB-RADIO-UK]

LOL thought you would like that.

[@williamhynds9213]

Has anyone got a video to show me how to program my ss6900n

[@CB-RADIO-UK]

Sorry but ive never programmed one myself nor seen a video :-(

[@williamhynds9213]

Fred in the Shed thanks

[@alanhewitt6607]

It might be caused by stray RF ,Getting into a poorly screened Pre-amp in the mic.

[@MrRichard57000]

haha ...omg to much smd on that board for me,but ill bet it does the job well.///cool video kid....

[@ruimiranda2453]

Sorry, I can already have someone to give me a Syrian 827

[@CB-RADIO-UK]

Left a link on the other comment. I think Ebay would be best.

[@Reverend-Rodger]

A lot of these newer radios mostly made in china, have audio problems starting with the cheaper audio amps that they put in to them. kzbin.info/www/bejne/fKGtfp6paLqJqa8 This seems to me to be systemic problem in newer radios and it is probably better to take the radio to a qualified/experienced expert. You certainly wont fix it by putting metal screwdrivers inside them and tweaking variable pots that need to be aligned with the correct test equipment.

[@CB-RADIO-UK]

Yes fair point. I was given the radio so i had nothing to lose. Normally i dont fiddle about with pots etc.

[@LightYerPipe]

Sounds to me like this needs an alignment with scopes etc. Another thing if you don't know what you are doing stay out of the radio. if you want to learn, which is good buy scrap radios and figure out how to fix them with the correct test equipment. never ever use metal screwdriver inside a radio.NEVER!!!!! Oh and lastly when these radios come out of the factory they are not tuned for 11 metres they are tuned for 10 metres so, when they do the changes to get 11 the whole radio has to be realigned from top to bottom on proper test equipment not by ear lol.

[@CB-RADIO-UK]

I think a lot you said is true and perhaps i should have used a scope if i had one. Alas i did not and i had issues to try and fix. However this was a swap radio so a freebie really and i had a go for a fix. Since this video was made ive been half way around the world on this rig with great reports and made many many videos (all on the channel) so i really did not do so bad.

[@robinbrown7019]

Would be great if you talked English

[@CBRadiouk1]

Hi Fred if you at the part of the video, where you was talking to dave. You will See the met was at full output, and never dropped. That is a sure sign of trouble on SSB, AS IS keying up with out talking and showing nearly full out put. Myself I would have turned this down until the meter reacted to my voice, dropping back when pausing. Any way hope all is well over there, this lock down looks to be helping the spread a little.

[@CB-RADIO-UK]

Thanks Steve. Yes you prob right. I sort of found a happy medium with the mod v power but iam no rig doctor. Darn death toll has umped from 180 to 383 in 2 hours. Aint out the woods yet bud.