richb1492

My Feedback: (4)

Has anybody used this receiver. I saw the price and its very cheap but is it any good. I heard it might be a rebaged Futaba

rcflier_gi

My Feedback: (2)

I have used them with no problems.

SMALLFLY-

My Feedback: (19)

since your asking for an opinion I owned 3 of these. They are rebranded futaba 127 Rx's. They worked but never range checked very good and seemed to be glitchy. I had a couple of hitec supremes so I compared them side by side on range checks and the Hitec supremes FAR outpaced the hobbico units. The hitec supreme is available at servocity.com for the same price as the hobbico and IMO is a MUCH better Rx. I still have 1 hobbico unit I keep for checking servos setups etc, but I just dont trust it enough to put it in the air. The 127's were known for weak filter circuits.

amcross

My Feedback: (2)

Just FYI -- while the R127DF, and the hobbico and Tower receivers, show a shorter ground range check than some other receivers, they flight range test as well if not better than other similarly priced items on the market. There is a difference in how the ground reflection affects the pickup of the receiver.

SMALLFLY-

My Feedback: (19)

One question. Why does the next best futaba RX jump up in price almost 3 times. Dont get me wrong I own and love a futaba 8u Transmitter and use several futaba servo's. I tested 6 feet off the ground (not in planes). I just think it's time the 127 was reworked.

amcross

My Feedback: (2)

Smallfly, thanks for your feedback. #1 reason? the 127 is produced in droves when compared to the others. Production costs always drop exponentially with increase in quantities produced....

Some running changes HAVE been made to the 127 over the years, including some in the recent past which has made some changes in how the ground range appears to the user. The important part however, is the unit remains essentially bulletproof in the air.

VE1FH

My Feedback: (4)

I'm not sure how this is relevant. It is true that ground proximity, ground conductivity and antenna alignment can all combine to produce differing antenna patterns ... that's why we have beam antennas, satellite dishes, etc. We must also remember that a horizontal (or nearly so) antenna less than 1/2 wavelength from the ground has a radiation pattern which is almost omnidirectional and which is characterized by an extremely high angle primary lobe. This is independant of how many elements, etc. Ham radio operators who use horizontal antennas on 160 and 80 metres are well familiar with this characteristic, unless they are sufficiently thick in the wallet to get these things way up high.

Vertical antennas, when erected over a ground of sufficient conductivity, do not suffer this handicap. The kicker here is "ground of sufficient conductivity". Vertical antennas over poor ground have the same issue as the horizontal one ... the pattern breaks up into very high angles.

This is certainly the case for our transmitters. How we hold the transmitter, what the case is made of, the conductivity of the ground, and how high above the ground we hold it all influence the pattern. But because it's usually so close to the ground and because it's over a poor ground (the pilot being between it and ground) it can be considered to have pretty much an omni pattern, frequently with a null off the end of the antenna.

At 72 MHz, a wavelength is about 4 metres; so the antennas have to be 6 plus feet off the to get into the half wave height above ground range.

If we consider a typical model airplane with an approximately horizontal antenna sitting a few centimetres above ground (the case for a range check), and we see some kind of null in the pattern as we do a range check, my suspicion would lie with some other conductive material in the near field of the transmitter or the receiver or indeed between them. It could be a fence, a control rod, another Tx antenna, who knows. This kind of near field obstruction can easily cause profound nulls in the marginal antenna systems we use.

A general lack of range, not related to a specific directional null, should be an indicator of poor Tx performance or, more likely, poor receiver performance from an improperly connected or extended antenna or a fault in the receiver front end.

Boy, that got long winded! Anyway, I just wanted to say that ground reflection would be highly unlikely to have anything to do with the kind of problem you describe.

amcross

My Feedback: (2)

Hi, John! I can't pretend to get anywhere near as technical as you have. Thanks for some neat stuff to learn!!

I can, however, tell you what i've been told, and what I've personally seen in the testing of R127s, which is that something in their makeup is directly affected by proximity to ground, as they range check radically differently when set up 3' off the ground as recommended vs sitting on the ground surface. AND they flight test identically to other receivers which are less susceptible to this proximity effect.

Hope that helps,
Sincerely,
Mrs. AnnMarie Cross
Senior Manager, Proprietary Services and Support
Great Planes Model Distributors
[email protected]
www.greatplanes.com
www.bestrc.com
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