pete59
Member
Please help me with an interference problem on my MF 65.It is a gas model and radio has some interference when tractor is running. It is wired straight to battery.Thanks.
radio interference
- Thread starter pete59
- Start date
Soundguy
Old Timer
- Joined
- Mar 11, 2002
- Messages
- 52,238
- Location
- Central florida
- Tractor
- RK 55HC,ym1700, NH7610S, Ford 8N, 2N, NAA, 660, 850 x2, 541, 950, 941D, 951, 2000, 3000, 4000, 4600, 5000, 740, IH 'C' 'H', CUB, John Deere 'B', allis 'G', case VAC
a few things you can do.
1, run an 'L' or a 'PI' filter
2, use carbon core 'supressor'wires and not oe style metal core spark plug wires.
3, use resistor plugs.
the latter 2 have spark intensity issues.. so if the L or PI filter handles the job.. I'd forgo the secondary resistors.
a L filter is an inductor (choke) inline with the power wire, and a single filter across power and ground(after inductor ).
a pi filter is the inductor in the power wire, and a capacitor across the power to ground both ahead and after the inductor.
I'd use a high farad value capacitor.. at LEAST 1000UF if not higher like 2200UF .. heck.. i've made filters for police cars with hi output alts back in the day, that used 4700uf and even 6800uf capacitors in a PI setup.
also.. a large value inductor will yeild beter results than one with lower 'henries' i'd reccomend 300uH minimum
for S&G's you could put a torrid core in the power distro too.
google choke input filter and capacitor input filter for more info.
ignore references to any butterworth filters
soundguy
1, run an 'L' or a 'PI' filter
2, use carbon core 'supressor'wires and not oe style metal core spark plug wires.
3, use resistor plugs.
the latter 2 have spark intensity issues.. so if the L or PI filter handles the job.. I'd forgo the secondary resistors.
a L filter is an inductor (choke) inline with the power wire, and a single filter across power and ground(after inductor ).
a pi filter is the inductor in the power wire, and a capacitor across the power to ground both ahead and after the inductor.
I'd use a high farad value capacitor.. at LEAST 1000UF if not higher like 2200UF .. heck.. i've made filters for police cars with hi output alts back in the day, that used 4700uf and even 6800uf capacitors in a PI setup.
also.. a large value inductor will yeild beter results than one with lower 'henries' i'd reccomend 300uH minimum
for S&G's you could put a torrid core in the power distro too.
google choke input filter and capacitor input filter for more info.
ignore references to any butterworth filters
soundguy
Soundguy
Old Timer
- Joined
- Mar 11, 2002
- Messages
- 52,238
- Location
- Central florida
- Tractor
- RK 55HC,ym1700, NH7610S, Ford 8N, 2N, NAA, 660, 850 x2, 541, 950, 941D, 951, 2000, 3000, 4000, 4600, 5000, 740, IH 'C' 'H', CUB, John Deere 'B', allis 'G', case VAC
pi better than L !!!
all that said.. the spark gaps are gonna make RF.
another option is an EI module....
all that said.. the spark gaps are gonna make RF.
another option is an EI module....
OP
pete59
Member
Thanks I will see what I can find.
Soundguy
Old Timer
- Joined
- Mar 11, 2002
- Messages
- 52,238
- Location
- Central florida
- Tractor
- RK 55HC,ym1700, NH7610S, Ford 8N, 2N, NAA, 660, 850 x2, 541, 950, 941D, 951, 2000, 3000, 4000, 4600, 5000, 740, IH 'C' 'H', CUB, John Deere 'B', allis 'G', case VAC
find? i doubt you find a pi or l filter.. you can simply hit a radio shack and make one.
1 inductor and one or 2 EL capacitors..
1 inductor and one or 2 EL capacitors..
Soundguy
Old Timer
- Joined
- Mar 11, 2002
- Messages
- 52,238
- Location
- Central florida
- Tractor
- RK 55HC,ym1700, NH7610S, Ford 8N, 2N, NAA, 660, 850 x2, 541, 950, 941D, 951, 2000, 3000, 4000, 4600, 5000, 740, IH 'C' 'H', CUB, John Deere 'B', allis 'G', case VAC
ps.. don't install anything inline with ground.. leave ground intact. only install inline devices like the inductor in the power wire... of course capacitors can reference ground.
installing an item in the ground line will create a potential difference, ground loop and hum sometimes..
installing an item in the ground line will create a potential difference, ground loop and hum sometimes..
OP
pete59
Member
Could You please elaborate Soundguy as electricity is not my specialty or would a radio shack rep have an idea for a novice? I'm from the 8 track days.
ThomasH
Gold Member
If you search ebay or Amazon for a Legacy LN71 12 Amp Noise Suppressor, I think that is what you are looking for. It installs in the 12 volt power supply line at your radio (as close to the radio as possible) and is simple to hook up.
k0ua
Epic Contributor
Ok my 2 cents... what is the problem? Ignition noise? Pop pop sound at idle andincreases to a buzz with increasing RPM from the spark plugs and wires? or whine from alternator? a high pitched whine sound that varies in pitch with rpm's. If it is ignition noise, first thing is switch to carbon filled wires and suppressor (resistor) plugs. If alternator whine then a choke/filter is called for. Also make sure the antenna coax shield is grounded at the antenna well. Also grounding and bonding of chassis parts is important. You can go to this site: K0BG.com and look under the ignition tab for starts.. then look under bonding and grounding for ideas. Note also the information on wrapping the wires with flexible copper tape.. Lots of good information on the K0BG site. It is amateur radio focused, but the information applies to your receiver also.
James K0UA
James K0UA
OP
pete59
Member
Thanks Gentlemen a noise suppressor is on order.I have made radio's and tachometor in high school but that was 35 yr's ago, didn't want to fry a perfectly good radio.