Model Boat Mayhem

Technical, Techniques, Hints, and Tips => Radio Equipment => Topic started by: catengineman on April 29, 2007, 08:25:26 pm

Title: receiver types
Post by: catengineman on April 29, 2007, 08:25:26 pm: I have a question (sorry to keep asking but if I don't know then it is better to ask those who do)

What is the difference between a single conversation receiver and a dual conversation receiver apart from the obvious
would they be interchangeable? if say they were both 40 MHz had the same number of channels and made by the same company.

ie: Futaba have two receivers on their web, look the same, channels same, numbers same but suffix is F or DF
it just states which type you want. now if the better type will work with my FX18
I know I have to fit an extra if I want to go over to PCM rather than the PPM I use at the moment (I think)

Thick Richard,
Title: Re: receiver types
Post by: Scottie on April 30, 2007, 01:18:15 pm: The difference between single conversion and dual is in both the transmitter and receiver. It is a difference in the way the signal is encoded and decoded in the RF module.

Single and dual conversion are NOT interghangeable.

Scottie.

Quote from: catengineman on April 29, 2007, 08:25:26 pm
I have a question (sorry to keep asking but if I don't know then it is better to ask those who do)

What is the difference between a single conversation receiver and a dual conversation receiver apart from the obvious
would they be interchangeable? if say they were both 40 MHz had the same number of channels and made by the same company.

ie: Futaba have two receivers on their web, look the same, channels same, numbers same but suffix is F or DF
it just states which type you want. now if the better type will work with my FX18
I know I have to fit an extra if I want to go over to PCM rather than the PPM I use at the moment (I think)

Thick Richard,
Title: Re: receiver types
Post by: gribeauval on April 30, 2007, 01:41:41 pm: Read this page and check out the section labelled myths,

http://www.phoenixmp.com/articles/rc-systems.htm (http://www.phoenixmp.com/articles/rc-systems.htm)

I have used both single and dual conversion receivers with my Hitec Lazer 6 transmitter, just use the correct crystals, dual or single conversion in the receiver.

Mike
Title: Re: receiver types
Post by: cbr900 on April 30, 2007, 03:14:40 pm: As Gribeauval has stated I also use single and dual conversion receiver with the same transmitter which is as far as I know a single tranny...........

Roy
Title: Re: receiver types
Post by: Scottie on April 30, 2007, 03:17:40 pm: I stand corrected... sorry, that was what I was told by a so-called 'expert'.

Scottie

Quote from: gribeauval on April 30, 2007, 01:41:41 pm
Read this page and check out the section labelled myths,

http://www.phoenixmp.com/articles/rc-systems.htm (http://www.phoenixmp.com/articles/rc-systems.htm)

I have used both single and dual conversion receivers with my Hitec Lazer 6 transmitter, just use the correct crystals, dual or single conversion in the receiver.

Mike
Title: Re: receiver types
Post by: catengineman on May 01, 2007, 12:21:44 am: Thanks chaps,

Yet more of the hard earned cash to go out of the bank :'(
Well at least I know now. Thanks again

Richard,
Title: Re: receiver types
Post by: Doc on May 01, 2007, 05:23:18 am: Without getting too technical, a single conversion receiver means that the received signal is converted from one frequency to another frequency which is easier to work with. A dual conversion receiver just means that there are two 'steps' to that frequency conversion, primarily because it can get rid of some things that just aren't needed/wanted in that 'extra' step. If the signal is strong enough in relation to all the other signals present, a single conversion receiver will work just as well as a dual conversion. That usually means that it's very slightly more prone to interference than the dual conversion, but in most cases, it just isn't going to be much difference over all. There are also triple conversion receivers, and in some instances four stages are used instead of three. As far as R/C'ing is concerned those three and four stage thingys are a complete waste of money, just not too practical or useful.

As for the modulation method, PPM, PCM, PWM, 'pickle in a pear tree', etc, the transmitter and receiver both have to be of the same type. If not, the receiver will have absolutely no idea what the @#$ transmitter just said to do, so will most likely do nothing (if you're lucky). Is it possible to change from one mode to another? Probably, but the cost is going to be a huge factor, no idea if it would be worth it, not to me anyway.
- 'Doc
Title: Re: receiver types
Post by: catengineman on May 01, 2007, 02:10:45 pm: The splurge in the manual says I can change between PPM & PCM but sa you know this will require the correct receiver etc.
For now as I'm still green to this stuff I'll stick with what I have PPM 40mhz Xtails then at a later date I may investigate the PCM route.

Richard,
Title: Re: receiver types
Post by: HS93 (RIP) on May 01, 2007, 03:09:22 pm: And there is PCM 1024 Dual Conversion Receivers

Peter
Title: Re: receiver types
Post by: catengineman on May 01, 2007, 04:04:38 pm: ???

Richard,
Title: Re: receiver types
Post by: catengineman on May 01, 2007, 04:14:10 pm: I'm off to slavery for two weeks so see you all after.

Richard,