Running 75mhz in the low sixties channels

[eckloss]

So, I noticed I had quite a few reception issues with the two boats I brought to Carmel. One was channel 77 and the other 86. I know of at least one other person who had the same issue, running in the 70's. It was suggested by more than one that running in the lower and mid 60's channels may improve signal. I'm curious as to why exactly. I'm trying to understand this all better before I go and swap out all my higher channels for lower ones.

[crueby]

The times I have had reception problems it was solved by capacitors on the motor and once needed ferrite rings on the motor leads, in a hull where everything was very tightly packed. Never noticed a difference in channel, though I usually run in the 80s.
I have no knowledge of the benefits, if any, of lower channels, will leave that to others.
Chris

[subdude]

Same as the real boats. Lower frequency = better water penetration.

That said, I run 85 most of the time with no issues.....

Jim

[JWLaRue]

While it it true that the lower channels are a lower frequency, let's not overstate the difference. Channel 61 is 75.410 MHz and channel 90 is 75.990 MHz. In the scheme of things, not a difference that we're likely to notice.

Before going through the exercise of changing channels I'd look for other, more likely, causes of poor radio reception. In addition to the ones Chris noted, antenna placement is a big factor too.

-Jeff

[crueby]

A break in the conductor inside the antenna can cause same issues. Or a worn spot in the insulation letting the wire touch metal parts. If using a BEC, try unplugging that source, ESC or whatever, and plug in a reciever battery to eliminate that as a possible cause. Same with each servo, swap out if possible.

[bob_eissler]

I use channel 69 and had problems with 2 boats. The Lafayette has a polk seeker 6 that lost reception on the left hand side. After I got out there and pushed it towards shore it worked fine. Next I had extremely short range on my Type 9 and after the experience with the Lafayette I just pulled the boat out of the water. Wished I had pulled the sub-driver out and checked it. The sub-drivers have a bolt thru the bulkhead for a antenna connection which is gooped with silicon for insulation. Seems like the connection had gotten scraped and the antenna was shorting to the water there. Gooped more silicone on it and problem solved, could have been easily fixed there.
I know Pete was having some frequency issues.
One other thing, I have Polk transmitters that automatically check for interference when turned on like Pete does. A couple of times I kept getting the frequency busy message and it would't turn on. This can happen just because there are a lot of transmitters close to your frequency but does not necessarily mean that there was someone on the same frequency.
Also garage door openers and other devices can cause interference.

[eckloss]

I'm not saying this was the only source of my issues, just trying to say it is one more thing that I can control in the long line of successfully piloting a boat.

[eckloss]

Chris: what flavor of capacitor do you use?

[crueby]

Chris: what flavor of capacitor do you use?

Usual is 0.1uf ceramic capacitors, one from each post of the motor leads to the case, can also add one across the leads. Can make a big difference on some motors. Here is a link to a good description:

https://www.pololu.com/docs/0J15/9

Chris

[eckloss]

So these will work?

https://www.amazon.com/Projects-B-0002-C11-Ceramic-Capacitor-0-1uF/dp/B00E6PNOXU/ref=sr_1_1_sspa?keywords=0.1uf+ceramic+capacitors&qid=1567020147&s=gateway&sr=8-1-spons&psc=1&spLa=ZW5jcnlwdGVkUXVhbGlmaWVyPUEyUE5YQUNSUk1YS1QxJmVuY3J5cHRlZElkPUEwNDA5OTIyMzRMVEZSTjY0QUY1TCZlbmNyeXB0ZWRBZElkPUEwMDc3NzkzM05XQzk0QTM1MlQzTyZ3aWRnZXROYW1lPXNwX2F0ZiZhY3Rpb249Y2xpY2tSZWRpcmVjdCZkb05vdExvZ0NsaWNrPXRydWU=

[crueby]

So these will work?

https://www.amazon.com/Projects-B-00...NsaWNrPXRydWU=

Yup! Thats the right kind.

[KevinMC]

While it's true that a lower frequency signal will penetrate the water better than a higher frequency one, there's a "scale of change" that needs to be kept in mind. Speaking in relative terms, changing from 75.990MHz (Ch 90) down to 75.410MHz (Ch 61) is not actually that big of a change. Moving from say 75.xxx MHz to 27.xxx MHz ought to at least get you a measurable improvement.

I was running on Ch 80 all weekend, and although I had a few hits here and there the only trouble it caused me was it interrupted my sustained submerged partols...

[cheapsub]

So, I noticed I had quite a few reception issues with the two boats I brought to Carmel. One was channel 77 and the other 86. I know of at least one other person who had the same issue, running in the 70's. It was suggested by more than one that running in the lower and mid 60's channels may improve signal. I'm curious as to why exactly. I'm trying to understand this all better before I go and swap out all my higher channels for lower ones.

sorry a bit late, just curious.
what type(brand) of Tx and Rx you are using?

also did someone transmitting a channel +/-, next to yours?

oxidation at crystal socket , corrosion/black death inside receiver antenna.

[pirate]

E,
Trying to get a hold of you. Looks like your Mac.com mail may not be good any longer.
Looking for some
Photos of your 1/72 Seawolf.
Pete
Info@submarineworks.com

[thor]

If it is a single conversion Rx, depending on the OEM tuning, they can more sensitive to channel than dual conversion Rxs.