First, an on-topic response to Garth's question:
Use your receiver before your transmitter. With your manually-operated antenna tuner in-line and located near the generator (transmitter) end of your antenna system's feedline, use it, essentially, as an outboard pre-amplifier for your receiver. Listen to the background noise level or any weak signals you can hear. Tune the weak station for best received signal strength, utilizing your receiver's bar-graph, analogue "S" meter, or even your ears. Even if you are using a grossly improper antenna for the frequency you are interested in transmitting on, this technique will get you close enough to a proper match to allow you to transmit for a VERY short time (hopefully) without damaging your transmitter. Be sure to use the LOWEST RF power setting possible before setting your antenna tuner to its' final values, assuming it is manually operated. Also, an antenna tuner near the transmitter end of your antenna sytem's feedline will NOT change the performance of your antenna system at all. It is only a "feel good" device that will keep your transmitter from turning into a melted chunk of (formerly) semiconductor devices. Such a device's sole purpose is to allow the transmitter to operate into a load that matches, as closely as possible, it's designed output impedance.
Now for the silightly off-topic that seemed to follow other respondents:
Railroad telegraphers were, arguably, the first "users" of S.F.B. Morse's codes. I am not even certain I am giving credit to the correct chap, hee. I digress ...
As a teenager, I was privileged to know a gent named Harold West of Westype Printing formerly located near Chicago, IL. Mr. West had been a landline (wired) telegraph operator for the Chicago Tribune back when. I had only recently, at that time, become interested in SWL, ham radio, electronics, etc. On 40M CW out of the blue I heard a signal that confused me. Not TOO unusual (hee) but I chose to ask Mr. West about it and it is a technique that I still use. I heard what my (then) young ears interpreted as <I E>. Huh? Harold informed me, with a grin and laugh, that I must have been listening to a couple of OT's (Old Timer's). What I had copied was not the International Morse letters I and E with a dot spaced length of time between them but rather the old Continental Code letter <C> which is defined as the same code elements I had copied. This was a RR ops way of being certain that the line he was about to transmit on was Clear of any traffic. Indeed, the ops probably interpreted that signal they sent, in their mind, as <Clear?> without the formality of an interrogative signal (question mark). After 30+ years using Morse's International Code I sumtimes use a few shortcutz 2, hi.
To continue (sorry), if the line was in use when an op copied the <C> signal, the correct response was (Internationally-speaking, hee) <I I> which I believe corresponds to the Continental Code's letter <Y> possibly meaning a response in the affirmative and that the station questioning the availability of the line should stand by (QRX, <AS> sent as a pro-sign and one International Morse character, etc.)
The most important facet of communications is the same now as then: as long as both "ends of the circuit" know and understand what the meaning of any "shorthand", abbreviation, pro-sign and the like is, then everything is all right.
BTW, I generally follow my <I E> pro-sign with the more widely in use (these days) <QRL?> Also, one disturbing thing I have noticed of late. Whatever signal you use to check a frequency before sending CQ, <TEST>, etc., please ... Please ... take a second or two to listen for a response to your question. Yes, I know ... we live in a hurry-up world where all picoseconds of time are precious but spending a second to eliminate, or at least reduce, QRM is worth it, ne c'est pas?
CU in the ether.
The difference between adventure and ordeal is ATTITUDE !