In essence, you have a radio which can be set up to give you eight completely different flight set-ups for each model. There are ten model memories in the transmitter itself, which can be increased to sixteen by fitting an optional 'CAMPac'.

Yes, this does suggest that you can have a total of 128 (8 times 16) different set-ups, but beware, the actual total number available is, in fact, 50 in the transmitter and an additional 22 in the 'CAMPac' and each of these must be assigned before they can be used. Don't fret, you can still have five different set-ups for each of sixteen models and a couple of set-ups to spare!

As I said before, the 'T9ZHP' is not the most user friendly device that we have met - don't look for swashplate mixing in the 'Helicopter' menu - it's in the 'Model' menu!

Fverything is selected by means of a three letter code which is accessed via various menus. Having selected the item that you need, you are then let into an entry screen which may, itselt lead on to several 'pages'. Here again, you have abbreviations and a form of 'shorthand' to learn. Having made the necessary adjustments, you will be presented with an 'END' or 'PRE' flag, both of which will return you to the previous menu. In some cases you are presented with a 'SWT' flag which puts you into the 'Switch Set' screen which allows you to select the switch required and set the sense in which it operates. In some cases, the required function can be operated by a pre-set stick position.

A full list of the functions available, when set to the 'Helicopter' option (there is also an 'Airplane' option and three different 'Glider' options), is as follows. Take a deep breath:

System Menu

MSL Model selection - selects any one of ten model memories.
VLT Voltmeter - shows transmitter and receiver battery voltages with a choice of 0, 250, or 500 mA load on the receiver battery.
TAC Tachometer - built-in digital phototachometer with a choice of 1, 2, 3, 4, 5, or 6 blade operation.
SRV Servo Test and Bargraph Display - gives a bargraph display of all channels and allows all servos to be simultaneously operated slowly from end to end.
TRN Trainer System - allows 'buddy box' trainer system to operate on selected channels.
DTN Data Transfer Function - transfers model or function information from one transmitter to another.
CPM Copy Model Function - copies information from one model memory to another within the transmitter or 'CAMPac'.
CPC Copy Condition Function - copies individual model flight modes between model memories
PAR Parameters - sets the auto power-off delay and the screen contrast.
UNA User Name Registration - allows the entry of a ten character 'user name. Both this and the model information can be protected by a four character 'password'.

Model Menu

CSL Condition Select - assigns each flight condition to a memory location.
TIM Timer Function - sets two separate timers to 'count up' or 'countdown' mode, sets starting time and allocates to a switch if required.
F/S Failsafe Function - sets each channel to either 'hold' or 'go to preset position' on failsafe.
PMD Pulse Mode - switches between PPM and PCM.
REV Servo Reversing Function - reverses each channel as required.
FNC Function Change - allocates sticks and trim levers to specific channels. Is used to change stick mode and allows crossed trims if required.
RST Data Reset - resets all, or a selected portion, of stored model information.
CUT Engine Cut - defines a switch which can be used to cut the engine. Only operates when throttle stick is already in the low position.
CHD Condition Hold - sets a maximum figure for the throttle high position. Used as a safeguard when making adjustments.
TYP Type Selection Function - sets model type to 'Helicopter', 'Airplane', or 'Glider (2,4, or 5 wing servos)'.
CH9 Channel 9 Definition - assigns a switch and switch direction to operate the ninth channel.
MNA Model Name Definition - allows the entry of an eight character model name.
ALT Alternate Switch - allows the springloaded switch 'SW (H)' to be changed between 'pull-for-on' and 'pull-on/pull-off' operation.
THR Throttle Curve - selects linear throttle or 'active throttle curve' (curve set elsewhere).
SWH Swashplate Type - selects between five commonly used swashplate set-ups, including 3 or 4 servo CCPM.
RDR Rotor Direction - sets rotor direction to clockwise (CW) or anticlockwise (CCW) for proper mixing direction.
INV Inverted Pitch - activates full inverted system with offset pitch.
PIT Pitch Curve - selects linear pitch or 'active pitch curve' (curve set elsewhere).

Helicopter Condition Menu

ATV Adjustable Travel Volume - sets the maximum throw of channels I to 8 each side of centre. Also sets up to 5 second delay on any change of control position.
APR Adjustable Function Rate - allows throw, etc. (including expo) of channels 1 to 8 to be changed for each flight condition.
D/R Dual Rates and EXP Curve Setting - allows the rate (including expo) of any three channels to be changed by one switch.
PMX Programmable Mixing - five free mixers which allow any two channels (1 to 8) to be mixed in three different manners('linear', 'offset' or 'hovering').
STM Subtrim - offsets servo centres.
TOF Trim offset - works similarly to subtrirn but allows a different setting for each flight mode.
CNA Condition Name Registration used to name new active flight condition (i.e. 'IDLE3').
PCV Pitch Curve - allows pitch curve to be set at 13 points.
PHV Hovering Pitch - sets the range of the hovering pitch adjustment and assigns it to a trimmer. Can be different for each flight condition.
PTM Pitch Trim - allows the whole pitch curve to be moved up an down by an adjustable amount by any selected trimmer.
TCV Throttle Curve - allows throttle curve to be set at 13 points.
THV Hovering Throttle - sets the range of the hovering throttle adjustment and assigns it to a trimmer. Can be different for each flight condition.
HOF Hovering Offset - sets the point at which the ATS system changes from 'up' mix to 'down' mix.
HLD Throttle Hold - freezes the throttle at a preset point. Can have its own pitch curve.
SWP Swashplate Type - mixes swashplate movement into throttle and allows 'phasing' of swashplate.
P>R Pitch to Rudder Mrxing - also known as 'Rev Mix' or 'ATS'. Allows rudder to automatically compensate for torque changes.
R>T Rudder to Throttle Mix - compensates for changing load on tail drive.
GYR Gyro Sensitivity - allows the gyro gain to be changed by a switch or automatically by rudder deflection. Very useful with proportional gyro.
ACC Acceleration - similar to rudder to throttle mix, but with adjustable delay.
INV Inverted Pitch - sets high and low pitch limits for inverted switch.
TRM Digital Trim - sets the sensitivity of the trim buttons.

You do get a lot for your money! That's just the programming - using it is something else.

Any experienced helicopter flyer will find that most of the above features are selfexplanatory. Once you have got to know the codes for the particular functions that you use most, and how to find them, it is just a matter of setting them up to suit the model. Well, almost!

Mention is made above of the fact that each 'Flight Condition' needs to be assigned. In fact, there are four standard conditions that are already assigned for each model memory; 'Norml' (yes, that is spelt correctly), 'Idle 1', 'Idle2' and 'Hold'. You can add four more and they can be called anything that you like (5 digits maximum). These extra 'Conditions' each have to he assigned to a vacant spot in the memory. Important fact No.1.

To do this, you go into the 'System Menu' and access 'CSL' ('Condition Select'). There you will find a list of the Flight Conditions and their memory location. Assuming that you have 'Model 1' selected, these will read as follows:

D: 01-NORML
2: 11-IDLE1
3: 12-IDLE2
4: 13-HOLD
5: 00-NULL
6: 00-NULL
7: 00-NULL
8: 00-NULL

What this is telling you is that the four preset Flight Conditions for Model 1 occupy positions 1,11,12 and 13 in the memory, with the other four conditions being unallocated. Before telling you how to allocate them, it is most important to note that the order of the conditions in the list is in reverse order of their priority. In other words, 'HOLD' over-rides all the other conditions. 'IDLE2' over-rides all except 'HOLD' and so on. Important fact No.2.

Let's assume that you wanted to set up a special flight condition for 540 degree stall turns. If this condition was to be put in position 5 it would over-ride the 'HOLD' condition and you would not be able to perform an autorotation while your special condition was turned on. This could be dangerous! The answer here is to move the 'HOLD' condition to position 5 and insert your special condition above it. If you want to use all eight available conditions, the 'HOLD' will have to be at position 8 to ensure that it can over-ride everything.

To allocate a memory position for your special condition, you go into the Condition Select menu and press the pushbutton which is labelled 'LST'. This gives you a list of memory locations and what is stored in them. By pressing the button labelled 'NXT' you can page through the list until you find a vacant one. The vacant ones are un-named and are identified by a 5 digit number (00001, etc.). Remember this number and press 'END' to go back to the previous menu. If you select one of the un-allocated conditions, you are then presented with a box which will allow you to enter the number that you noted. Having done that you can press 'SWT' and select a switch to operate your new Flight Condition. You then need to go to the Helicopter Condition Menu and select 'CNA' which will now allow you give the condition a name.

I said in the original review that I did not like the digital trims. After using the equipment for a while, I still don't like them, but I am finding ways to make use of them.

For those who are not familiar with these, the trim levers only move a very small distance and are actually a switch. Applying pressure will increment the trims in the desired direction and this is shown on the display. My problem is that there is no 'feel' of where the trims are, and what used to be an automatic reaction simply doesn't work any more because you have to look at the display. Actually, I never realised just how much I used the trims until I tried the '9ZHP'.

The actual amount that the trims are incremented can be adjusted, so that the action can be fine or coarse, as you require. Increasing the pressure on the switch makes the trim increment faster. Nonetheless, any trim change takes time. I find this arrangement particularly irritating when you come to start the motor. Most motors require the throttle to be opened a little for the first start and this is easily done by advancing the trim - the throttle stick itself is too coarse - not so with the '9ZHP'.

My cure (?) for this is to allocate a special flight condition called 'START' which advances the trim by a preset amount when a particular switch is operated. This works reasonably well, but could be dangerous in some circumstances.

Nonetheless, this is where the system is actually useful because you can have a different set of trims for every flight condition, which means that such things as 'Stunt Trim' are unnecessary.

The trims themselves can be set to 'normal' or 'ATL'. ATL is used on the throttle trim and means that the trim only works on the low end. The trims can also be set to 'combined' ('CMB') or 'separate' ('SEP'). Separate means that you can have a separate trim for each flight condition - well almost.

The reason for the qualification is that you have to tell the system that you want each trim to be separate for each flight condition. Important fact No.3.

In other words, you have to select each flight function in turn, and set each trim in turn to 'separate', which could mean 32 individual operations!

The advantages of this system, of course, is that you can have some trims separate and some combined. For example, you could have separate trims for 'NORML' and 'HOLD' and combined trims for everything else. However, from experience, you may want to change this on the flying field and it is simpler to set everything to 'separate'. Of course, the default setting is 'combined'!

Another advantage is that the trim display shows you two positions; the current setting and the setting which was used the last time that you accessed that model memory. At first, I thought that it retained the setting from the last change of trim, which I liked. However, if you go to another model memory and then come back, the setting is lost. I don't like that!

You may think that the separate trim for each flight condition would allow you to set a tail rotor offset in the 'HOLD' condition. It will, but my experience is that it does not have enough range to feather the tail. To do this, I originally found it necessary to add 'Sub Trim' ('STM') as well. Then I discovered 'Trim Offset' ('TOF')! This, and STM, can also have a different setting for each condition. That makes three different ways of changing each trim for each condition. Important fact No.4.

I thought long and hard before using that word as a heading. Setting up the transmitter for a new model can be very time consuming. Let's stress here that there are ways of copying information between flight conditions and between model memories, but this is far from straightforward and you need to understand how the memory works to avoid making mistakes.

What is important is that you cannot copy the information about switch locations and is necessary to set up each model memory to the switch settings that you want. If you want to copy all of the information about a particular model into another model memory so that you can try various changes (good practice), you still have to set all the switch information in separately. Important fact No.5.

When copying between flight conditions, you are actually copying between memory locations. Once you understand this it is possible to copy information between flight conditions and model memories simultaneously (i.e. between 'IDLEl' on Model 1 and 'IDLE2' on Model 5. However, the possibility for mistakes is considerable.

The '9ZHP' has received lots of coverage in American hell magazines because of the fact that it has 'multi-point' tail mixing. While I agree that this is a good thing, the way in which it is set is not at all obvious. It is accessed by selecting 'PIT TO RUD' ('P>R') from the Helicopter Condition Menu.

When I first tried to set this up, I looked just about everywhere to find a way of setting the rotor direction and decided that I could do without it by setting the mixing direction in the 'PIT TO RUD' screen. I later discovered that the rotor direction can be set by 'RDR' in the Model Menu. Swashplate mixing ('SWH') and switched inverted ('INV') are also found here. Important fact No.6.

I had great difficulty with the 'P>R' function until I followed the sample set-up shown in the manual. From this it became clear that you have to set in values for each of the intermediate mixing points before you can set the overall mix percentage. In other words, you have to define the 'shape' of the curve first and then set the amount of mixing. I still don't fully understand the system but I have now got it working to my satisfaction. As you might expect, you can set a different mix curve for each flight condition and every one has to be set individually!

The idea here is to let you stop the motor by means of a selected switch. It is accessed via 'CUT' in the model menu. It operates when the throttle is below a preset value and closes the throttle fully, without any adjustment. This can easily damage the linkage from the servo, so I found it much better to set a Flight Condition called 'STOP' and operated by the spring-loaded Trainer switch 'SW(H)'. This way, I can set the position that the throttle is closed to and allocate it a priority via the Flight Condition list. Otherwise, it over-rides everything.

This function ('CHD') allows you to limit the available throttle opening while you make adjustments to the programming with the engine running. This would be fine if it retained your existing setting for the low throttle position. Unfortunately, it defaults to maximum throw, which means that the motor will stop unless you have the throttle stick in an open position - not very practical. A straightforward 'freeze' of the throttle would be much more useful.

I did think about adding a Flight Condition called 'FREEZ' but that would call up its own throttle and pitch curves and not allow me to adjust the others..

This may not be the answer to your particular requirements, but putting all of the above together, we end up with a suggested list of Flight Conditions for a helicopter as follows:

D: 0l-NORML
2: 41-START
3: 44-STOP
4: 11-IDLE1
5: 12-IDLE2
6: 13-HOLD
7: 00-NULL
8: 00-NULL

This means that 'START' and 'STOP' over-ride the 'NORML' set-up, but are over-ridden by the two 'IDLE' curves, and 'HOLD' takes precedence over everything. You can add two more idle up conditions if you need them, remembering to move 'HOLD' down the list to the last position.

This is just one of the many transmitters available from a number of manufacturers which includes a graphic display of certain features such as control throws and pitch and throttle curves.

In many cases the pitch and throttle curves can be set at a number of points. In some cases the actual number and position of these points can be set by the user. In the case of the '9ZHP', we have 13 points, take it or leave it, which can, perhaps, be too many in some cases.

One thing which the '9Z' series has which seems to be unique to this manufacturer is the 'bargraph' display of all the channels. This is a very, very, useful device and must soon be copied by others. In fact, it's almost as good as including the pulse timing of each channel in the display, which is another thing that no-one has done yet.

However, we are still far from the ultimate radio, and there are many features of the '9Z' that could be improved. The same applies to all its competitors and, at the moment, it comes closer than most. I like it, but its usefulness depends to a great extent on just what you want it for. The average flyer is unlikely to do more than scratch the surface (literally), while the dedicated competition flyer with several models - possibly of different types - will soon find it indispensable.

Setting it up may be a continuing process and you will continue to learn. This can be very enjoyable and satisfying. Particularly when you find a way of doing something in the way you want.

The overwhelming advantage of the '9ZHP' lies in its switch versatility. You can literally have one switch for each manoeuvre, and none of the opposition can do that - yet.

1 Extra Flight Conditions each have to be assigned to a vacant spot in the memory.

2 Flight Conditions are listed in reverse order of their priority. The last one listed over-rides everything else.

3 You have to tell the system that you want each trim to be separate for each flight condition.

4 Each Flight Condition can have a different trim (four main controls), different Sub Trim (all channels) and different Trim Offset (four main channels).

5 You can copy information between Flight Conditions, but you still have to set all the switch information in separately.

6 Swashplate mixing ('SWH'), rotor direction ('RDR') and the switched inverted system ('INV') are all to be found in the 'Model Menu', not the 'Helicopter Condition Menu'!