I like the sound of it too.. but my mate Paul and i often chat on 10m FM in the mornings while he is en route to work .. (using his Motorola handheld) and so after sending my FT 920 away and waving a fond (but not tearful) goodbye to my FT 817 - i was left FM less. and, the only remaining HF set then was the backup set, a Yaesu FT-101 ZD MK III that i picked up of local Yaesu guru Harry, G3LLL a few months previous, a Sommerkamp FT 277 ZD ctually and it had no AM, no FM. No problem.
After half-heartedly searching on Ebay one evening while bored, a FM board, (sorry) a PB 2219 popped up out of the screen at me, there are several revisions i believe, and not sure of differences, but i think the end result comes down to either you end up with hum loops, off frequency on TX, no audio or such like, nice, because they're quite rare nowadays, you cant afford to sit and wait, and i dont know anyone apart from Harry himself who would know the differences either) but i wanted one, I had seen them go for silly prices, one for over £120, I doubt anyone bought this, as the whole HF set is'nt really worth that much more, but if you even contemplate selling something like this for such a ridiculous amount - Shame on You,
I'm constantly irritated by people's greed on Ebay in particular, - if you're one of those folks, you suck, and just wait till you need your stuff repairing, then you'll be moaning,
but i dont want to get off on a rant here..
Well, time moved on and i am now £36 lighter (still a little too high a price) and one sunny morning the FM board arrived dropped through the letterbox.. well almost, it was extremely well packaged, it appeared in a box the size of a toaster !
The ZD manual is helpful enough, up to a point, so i unscrewed the 2 short screws out of the IF unit ready for the 2 long 'post screws' and tried not to lose them.. you remove the screws here shown below .. this is where you mount the two standoff screws, that i didn't have....
if you're buying FM/AM board for a ZD, devise some way of mounting the board, its a little ingenuity or a junk box test really, old computer motherboard type bits were found and
so another root 'round one of the junk boxes revealed some hexagonal pillars with threaded tips, but they weren't quite long enough though.. metal ones are fine, if you can stack then, you're pretty much there, but a few grey plastic hexagonal stand-offs jumped out of the junk box at me,as did PC motherboard standoffs, threaded both ends, so i used these, as they were luckily the correct thread to go into the ZD, i've also seen the grey plastic kind of things before, not sure where they are from, or what they are for, you may know after seeing them, so they were both brought together unholy matrimony.. metal motherboard standoffs at the bottom, familiar grey plastic threaded bar on top.. you only need the board to be just over an inch and something abobe the main ZD PCB below, so 2 or 3 long screws that go into the ZD's chassis, same number of spacers to put the board on and then you're set.
this are the dual threaded end PC motherboard mounting posts
and with the 2 standoffs together, or long screws and spacers, or whatever way you do it, , as you see, the grey plastic hex has been screwed onto one side of the brass stand off here.. obviously this will have an effect (or not) on possible earth loops later on, and it may be a good thing to insulate or not. I'm not sure, the default way, and looking at the underside of where the screw holes on the FM PCB are suggest it wants to be earthed. but I didn't have the right bits, so i fitted it and worried about hum later.
so a couple of self-tappers into the top of these pillars and we were in business. I did try what seemed a more elegant solution with long threaded screws (cut to length) through slightly wider and metal tubes to support the board, but i didn't have 2 or 3 proper length screws and spacers.. junk box fail !
Harry G3LLL writes with regards to earth-loops and hum:
" Yaesu removed an earth connection from the rigs internal wiring loom to the vol / RF gain control, but later cut a slot on the underside of the FM board to isolate the mic input from the rest of the board and reconnected it back to the vol / RF gain control.
if you fit an FM board without the slot to a ZD with an earth wired to the vol / RF gain control, you will get hum on TX and possibly RX as well, so you'd have to remove the correct lead, - there are three lead screens wired to the 'earthy' end of the vol control, so use trial and error to see which one, when removed, cures the hum. conversely, an FM board with the cutout to a rig that does not have the earth lead connected you will find a unmodulated carrier about 100Khz off your receive frequency, in which case, find the screen that's not attached and solder it back with the other two." - (in Practical Wireless: March 2009)
Thank You Harry .. i had reports of audio hum on the mic on TX, so i spent a hour or so carefully swapping out the screen of the 3 coax's leads going to the Vol / RF gain control, cured, but easily overlooked.. depending on *which* rev of the FM board you end up buying ..
So, lets plug it in, and try to keep the magic smoke in the ZD if you can, for it is the magic which makes this makes all electric boxes work. There are 2 white, 3-pin connectors, P19 and P23, they are easy do do, P23 comes up the right hand side (with the rig front facing you) of the IF board and it plugs to the left hand pins ..
J2503, the other 3 pin (P19) from the rig goes to the only other 3 pin connector on the FM board, J2504. P19 probably wont actually stretch over to the wrong pins so, this is pretty foolproof. well, usually. the multi-way P20 plugs to J2506 on the FM board.
Now the coax-links. these are yellow and very pretty.
Unplug the yellow coax from J101 on the RF unit, and pop it onto J101 on the FM board.
and connect the yellow shielded cable to J101. This is the RF unit AFTER the board is fitted:
on the RF unit, unplug P11 - (the red shielded cable) into J102
so the fitted FM board looks a bit like this
and the pretty yellow coax, fitted :
and that should do it. i had to tidy this up too. you wont have to i bet.. looks like the ZD had a new tranny in once over ,,,
dont forget this : noisy round metal thing
and i see i have room for the other filter. maybe i'll pop up and look on Ebay one day. mind you, the standard Yaesu filter is more than good enough really, the MK III ZD's IF notch filter can be reversed into a notch 'pass' mode too, which is quite handy for CW or beacon monitoring, so dont need CW narrow. maybe I'll fit a fixed channel crystal for our local 28.495..
Hmmm.. all you need now is to keep below 100mA on TX and wait for some voices ...
now .. a switchable 100kc downshift would be handy on TX ..
Next time on 'Why is my rig broke' I investigate the frequency stability of the FT 101 ZD and try to learn how to fix the appropriate relay/dry joint/cap etc *not* using servisol ... but i promise it will have more low res pictures for us to enjoy.
