SPE EXPERT 1K-FA FAQ

MISCELLANEOUS

Q: What should I do to get the most from my linear amplifier?
A: It is strongly recommended an accurate reading of its User’s Manual, with particular care to its Section 11. “INITIAL OPERATION OF THE AMPLIFIER”.

Q: What is the data connector labelled RS-232 placed on my linear’s rear panel for?
A: It is for a remote connection to a master PC (see User’s Manual Section 15. “USE OF THE RS-232 PORT”).


ATU

Q: May I use my linear amplifier to transmit on frequencies beyond ham-band limits?
A: You are not allowed to do that since the linear amplifier is a FCC compliant device.
Wherever Local Governing Laws make it possible, it can be either ordered a custom version covering particular bands (eg. 27 MHz, MARS…) or a Full Coverage version (1.6 – 30.0 MHz) for commercial use only.
Ask us an offer when placing your order.

Q: I want to connect an external tuner to my linear amplifier’s output. May I bypass my linear amplifier’s internal ATU in such a case? Is there anything I ought to be careful with?
A: In order to provide for an internal ATU correct bypass you ought to consult the procedure described in the User’s Manual at Section 11.1, Item c), second note.

Q: Should I have to perform a new Automatic Tuning operation with the internal ATU whenever I switch to another frequency on my transceiver?
A: Absolutely not, since that operation could make things worse. All that’s needed to do is to perform an Automatic Tuning operation on all the sub-bands composing a band at the initial start-up of the linear amplifier as described at Section 11.1 of the User’s Manual.
This is the best way to get a fully automatic linear behavior.

Q: My linear amplifier is equipped on its front panel keypad with two keys labelled [<BAND] and [BAND>] which are for manual band switching. However those keys seem to be always disabled.
Which is their correct way of usage?

A: Those two keys are correctly inactive whenever any CAT interface is set, since an automatic band switching would be assured in such a case. Those function-keys get enabled when the CAT interface gets disconnected (“NONE” setting…).

Q: My linear amplifier has got several functions placed into the “MANUAL TUNE” display sceen. What are they for and how can I profit by their correct usage?
A: On the initial setting of the device those functions could be useful to manually “fine-tune” an antenna matching on a sub-band (an operation which seldom needs to be carried out…), to know the currently switched sub-band as well as the actual working frequency.
Section 18.5 of the User’s Manual shows a description of these functions.

Q: Which is the worst antenna mismatch that I could try to improve using the Automatic Tuning function of my linear amplifier?
A: The worst case of an antenna mismatch that you can deal with is 3:1 (2.5:1 on 50 MHz…).
The internal ATU, on some bands, can do a lot more but that is a not recommended practice since there could be generated some extremely high internal voltage rates which could be very dangerous for the linear amplifier’s integrity. So there must not be performed an Automatic Tuning operation on heavily mismatched antennas (expiration of the warranty terms…).

Q: When my linear amplifier is switched into OPERATE mode I can get even rather high reverse power readouts (PW REV) from its display. Could they be a symptom of a not correct antenna matching?
A: Absolutely not. In such a case the PW REV readout is just the overall power of the harmonics generated by the linear. All the linear amplifiers generate them (that is the reason why filtering circuits are put at the amplfier’s output…) but only the EXPERT is able to show that measurement result.

CAT

Q: What is CAT and which are the benefits from a correct usage of that kind of interface which is embedded into the most ham-band transceivers?
A: CAT (Computer Aided Transceiver) interface enables the linear amplifier to know the transceiver’s working frequency since it is still switched into RX, this way the linear amplifier is able to immediately match its switched antenna. Thus, when a transmission starts, everything is propely set and ready to work assuring, this way, the best automatic response and safety of operation by the device. Whenever a CAT interface is present its usage is an absolutely recommended practice to follow

Q: My transceiver is equipped with a CAT interface which is supported by the linear amplifier.
However my problem is that this interface has been already linked to a PC which controls the radio equipment. May I also propely connect the linear to the CAT physical line in such a case?

A: Yes that is possible in many cases. You ought to consult the User’s Manual at Section 14.

Q: My transceiver is not equipped with a CAT interface. May I have automatic tuning frequency tracking in such a case?
A: The linear amplifier is equipped with an embedded frequency-counter stage which enables it to detect and measure the actual TX frequency. So a correct band and sub-band detecting and switching gets assured since after the first transmission instants.

ALC

Q. Why is it advisable to link the linear to the transceiver using the ALC driving line?
A: The ALC link is essential and it is a key point of the EXPERT 1K-FA. Other linears just use their ALC line to limit overdriving. The EXPERT linear amplifier uses its ALC driving line to adapt the transceiver’s output power to its requirements and to have the best linearity. No need to manual setting actions, then.

Q: My transceiver is not equipped with any ALC input socket. How should I do not to run the risk to overdrive my linear amplifier?
A: There are some transceivers which allow a digital control over an “ALC-like” link (e.g. Flex-Radio equipments – see Section 18.22 of the User’s Manual …). On all the other cases a manual action over the transceiver’s output level adjustment is required.

Q: My transceiver is equipped with an ALC connection which handles positive-going voltage levels only. May I link it to my linear amplifier?
A: No, of course you can’t do that. Since negative-going voltage driving is a standard, it is unlikely that a consolidated manufacturer could make such a design mistake.

POWER SUPPLY

Q: My home’s mains source is not rated at 230 Vac. What should I do for a correct usage of my linear?
A: Mains input voltage can be varied over a selected series of choices. Consult Section 7 of the User’s Manual to have more particulars.

Q: I would like to automatically switch on/off my linear amplifier whenever I switch on/off its connected transceiver. How can I do that?
A: That operation can be performed by using the 12 Vdc power source that is usually available on the rear panel of many transceivers when they get switched on. Each one of the two CAT sockets on the rear panel of the linear amplifier has a specific input function (pin #8..) that can be used to switch on/off the device using that power source. It is also possible to switch the linear amplfier on/off using the RS-232 port connection (See Section 15 of the User’s Manual).