If you are checking the gain of the whole K2 RF and IF strip less the modification of the IF gain by the effects of AGC, yes, it is possible to use a lower output from the signal generator. However if you need to go into troubleshooting in greater depth, the 270mV / 756mV pk-pk found at the 2nd crystal filter output (product detector input) is far from the lowest signal that will need to be measured. The input to the to the RX mixer Z6 with the preamp and attenuator switched off is listed as only 77mV / 215mV pk-pk after the nominal 6dB voltage loss going through the low pass/bandpass filters when 140mV / 392mV pk-pk is inserted at the antenna jack. Whilst this will seem a relatively high level there are several pitfalls to beware of. Firstly, the oscilloscope will probably be using a X10 high impedance probe which would only give 39.2mV pk-pk to the input of the oscilloscope. Secondly, most of the older oscilloscopes had a maximum sensitivity of 10mV pk-pk/cm and with this there could be a further caveat that the bandwidth of the oscilloscope was reduced on the lowest range. The common 5MHz bandwidth TV service oscilloscopes of the past came down to only a bandwidth of only 1MHz or so when on the 10mV range. This is not much use when trying to measure RF levels even on 80m. The high signal generator output level advocated by Elecraft in their K2 troubleshooting info though needed for the use of their supplied RF probe/DVM, may be of significance in doing the same measurement with some earlier oscilloscopes. Modern high bandwidth oscilloscopes with a maximum sensitivity of 1mV pk-pk/cm would fare much better on this score. You need to check out what your particular oscilloscope specifications are and that it can fulfil the task before jumping in with both feet to do the measuring. I approach the troubleshooting of the RX front end and similar measuring tasks by using an RF millivoltmeter with a high impedance probe. Was able to acquire a Racal Dana 9301A some years back and that will go down to 1mV FSD at up to 2GHz. This means that I can use much lower levels of RF injection into the antenna jack to do measuring in the RX RF section. Found it very useful to repair a JRC RX whose front end had been very extensively damaged by a nearby lightning strike. The problem is that modern RF millivoltmeters can be as costly to buy as a good signal generator unless an earlier tube type can be located. There used to be several types available from manufacturers like Heath that would measure RF quite successfully and now are available at very low prices. Bob, G3VVT
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