mikef Posted July 23, 2022 Share Posted July 23, 2022 My shiny new P2PK has had its first flights. They might have been its last but I was lucky. The model went into failsafe not all that far away. I haven't got the full flap elevator compensation sorted so the failsafe gave a rather steep descent. Luckily it re-linked quickly and I was able to power it back home. I will get the Radio link checked but I suspect the antennae are being shielded by the wing - that was certainly the limiting orientation on the range check. Range check (reduced Tx power) seemed normal but I won't fly again until I get a lot more. I have the the Multiplex DR 7 light Rx installed with its normal 140 ish mm antennae - pictures here. With hindsight, the installation looks extremely dodgy! I am a bit ashamed to post this but it might help others. How are others orienting the P2PK antennae? I plan to fit the 400mm antennae and set them up as one up and one down 45 degrees away from the fuselage boom and further behind the wing. 1 Link to comment Share on other sites More sharing options...
SteveH Posted July 24, 2022 Share Posted July 24, 2022 I managed to get my antennae a bit further down the boom and pointing slightly down. 1 Link to comment Share on other sites More sharing options...
mikef Posted July 24, 2022 Author Share Posted July 24, 2022 30 minutes ago, SteveH said: I managed to get my antennae a bit further down the boom and pointing slightly down. Thanks Steve. I have my exit holes where the hole on yours is at the aft end of the 'pylon'. Did you try there first? Link to comment Share on other sites More sharing options...
SteveH Posted July 24, 2022 Share Posted July 24, 2022 Hi Mike I tried that but the antennae interfered with the flaps in braking. I think the key is to get the antennae as far away from the wing as possible and pointing slightly down if possible. 1 Link to comment Share on other sites More sharing options...
mikef Posted July 27, 2022 Author Share Posted July 27, 2022 The receiver in question has now been checked against my two others of the same part number and it is down on range by quite a bit - tested on low Tx power. It goes into failsafe more easily and struggles to re-acquire compared to the 'good' pair, so it will be replaced. I have also obtained the 400 mm antennae and will fit those - belt and braces! I have been using Multiplex 2.4 gear for about 10 years and this is the first range problem I have seen. Royal Evo 9, HFMX module and RX-7-DR light Rx. I have had the Tx and Rx checked by the UK Multiplex service agent today who confirmed that the Rx was down on range. Link to comment Share on other sites More sharing options...
andyharrold Posted July 28, 2022 Share Posted July 28, 2022 I tend to fly a new model with a Rx that I have confidence in, and a new Rx in an old ic powered plane and fly it to about 1600' Only then, do I put them together. Link to comment Share on other sites More sharing options...
mikef Posted August 2, 2022 Author Share Posted August 2, 2022 The suspect receiver is on its way back to Multiplex and a good one is installed with the 400 mm antennae replacing the 150s. Range check in the garden is solid all the way where it was cutting out 3/4 length before. Proper range check to come on the flying field. 1 Link to comment Share on other sites More sharing options...
SteveH Posted August 2, 2022 Share Posted August 2, 2022 Mike - I usually slip some clear heatshrink tubing over the antennae to protect them from damage (especially the exposed tips). It also helps to keep them clear of the airframe (carbon) when the model is travelling fast. 1 Link to comment Share on other sites More sharing options...
mikef Posted August 4, 2022 Author Share Posted August 4, 2022 Range check at the field gave 70 metres on low Tx power with my standard checking set-up. Test flying is going well and the model is teaching me to fly it properly. I'm happy now - flew out four consecutive 10-minute training slots this evening in overcast conditions with a cool 7-12 mph wind. 2 Link to comment Share on other sites More sharing options...
Loppy19 Posted August 5, 2022 Share Posted August 5, 2022 Has anybody tried the so called enhanced antenna. This antenna is equipped with a balun. that is the black cylinder at the end of the antenna Link to comment Share on other sites More sharing options...
mikef Posted August 5, 2022 Author Share Posted August 5, 2022 3 hours ago, Loppy19 said: Has anybody tried the so called enhanced antenna. This antenna is equipped with a balun. that is the black cylinder at the end of the antenna Tell us more? Link to comment Share on other sites More sharing options...
MikevE Posted August 5, 2022 Share Posted August 5, 2022 I have some, but haven't tried them yet. Normal ones on the left, balun on the right. 1 Link to comment Share on other sites More sharing options...
RSH Posted August 5, 2022 Share Posted August 5, 2022 I have Multiplex receivers and have been using FrSky replacement antenna, but trimming the important end to be the same as the MPX antenna. Antenna replacements are then ground tested at distance on the MPX Profi which can display signal quality. Also recently bought some enhanced antenna and have just looked up the function of the balun. Now a little concerned that the balun may be tuned to a specific antenna length and if I shorten this, do I mess up the point of the balun. Any ideas anyone? Link to comment Share on other sites More sharing options...
simon_t Posted August 7, 2022 Share Posted August 7, 2022 On 05/08/2022 at 12:50, RSH said: I have Multiplex receivers and have been using FrSky replacement antenna, but trimming the important end to be the same as the MPX antenna. Antenna replacements are then ground tested at distance on the MPX Profi which can display signal quality. Also recently bought some enhanced antenna and have just looked up the function of the balun. Now a little concerned that the balun may be tuned to a specific antenna length and if I shorten this, do I mess up the point of the balun. Any ideas anyone? The length of coax shouldn’t affect the balun (also called ‘gain sleeve’ antenna). It is just an open ended tube, similar in length to the active element that is connected to the outer of the coax at the point where the shield stops. Simon Link to comment Share on other sites More sharing options...
Loppy19 Posted August 8, 2022 Share Posted August 8, 2022 Yesterday the enhanced antenna on my redundancy receiver made a BIG difference. From my log files, lowest VFR was 60% at 326M with a RSSI at 28! Will now put the enhanced antenna on the main Rx. Previously at 250M and say about 250M away I got a VFR of < 40% while the RRSI might drop to about 28. Before that without the redundancy Rx I have never knowingly lost control with a VFR at about 30% Link to comment Share on other sites More sharing options...
mikef Posted October 10, 2022 Author Share Posted October 10, 2022 I have now had chance to do some more investigation on the RX-7-DR light Rx. The suspect one that nearly cost me my new Prestigue 2PK was checked by Multiplex Germany with 'no fault found' but they did say that these latest receivers have a reduced range. I asked for my 'bad' receiver back for further testing but this was not possible and they sent me a new one that seems to be the same in initial testing. It seems to be less than half as sensitive as the earlier examples I have compared it with. 59 paces range vs. 37 in comparative testing. The 'suspect' receivers have a white wrapper compared to the silver wrapper of the earlier ones I have had. Anyone else had problems with a white wrapper version? Link to comment Share on other sites More sharing options...
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