President Lincoln II v3 cw mode testing

| junio 8, 2014

President Lincoln II V3 cw mode testing

President Lincoln II V3 cw mode testing

President Lincoln II V-3 10m (28MHz) all mode transceiver

Just received the new President Lincoln II V-3 mobile 10m transceiver. They delivered promptly (within 36 hrs) and seem to be the only company selling the latest version.

All the others are relying on customer ignorance to get rid of all their old versions and not being honest and reducing the price accordingly. Nevada also carried out upgrades from V1 to V2 in house leading me to make my purchase from them alone.

There really is no competition out there, go Nevada! Straight away I noticed that the clarifier must be moved to 2 o’clock in cw mode to hear stations coming back to my transmission. I had asked multiple reviewers for a simple test in cw mode, but all didn’t have a key or didn’t reply. Once over this disappointment, I noticed that on every commencement of transmission (i.e key closure) the set transmits an initial long «dah» tone independent of how long the key was closed.

This is very annoying when you want to begin a transmission with a «di» or if you hesitate too long between words and the rig unkeys then keys again with an unwanted long «dah». It was possible to work round these stupid flaws in the transceiver firmware, but I wish the reviews of these types of radio would test cw as part of their so called testing. The initial transmit error is by far the more serious problem for a cw operator, hopefully president will correct this glitch in future firmware revisions.

CW rx bandwidth seems to be asymetric around the centre frequency -3KHz -> 0 -> +1KHz (centre being around 600Hz audible tone) allowing anyone in that 4KHz range to be clearly audible. The clarifier is rx only and has +/- 1Khz travel which is sensible, but with +/- 150 degree for +/- 1KHz means roughly 7Hz per degree of rotation…as you can imagine this is rather lively to be comfortable. The clarifier knob is mounted on it’s own with no concentic control rings to get in the way (sensible), but it’s diameter is only 9mm so it’s hard to control.

The push buttons on the front panel seem very stiff, you have to hold the set whilst pushing till you hear a click. I can’t imagine this being acceptible for any type of operation except when the radio is secured to a surface. Maybe these will ease off as the set ages, time will tell.

Audio sounds poor compared to any Ham radio, with a high hiss which has nothing to do with background noise. This can be dulled by a «hi-cut» feature, but unfortunately it affects the intelligebility of rx’d stns also. In SSB rx, there seems to be an oddity in the audio that sounds distorted (image effect) if not absolutely tuned in perfectly. This leads to constantly titivating the clarifier which gets tiring. Hey ho mustn’t get too fussy…it does do what it says on the tin…just! Otherwise I worked a few stations without a hitch with tx good audio reports.

All in all I have a cheap 10m all mode that is really a CB with ideas above it’s station. I do believe that there is currently no other CB competition to it out there (if you wish CW mode), so if you have money to burn and simply must have a 10m only cw capable rig for the car then this is the only choice. https://www.youtube.com/watch?v=KDC-bm4hyGE

President Lincoln II V3 cw mode testing

What a difference a day makes. I have discovered some more detail on the firmware fault I described in an earlier post. The long «dah» at start of transmission seems only to occur when the input key closure duration is very quick. I connected a manual key and couldn’t see the problem I had before, although another problem has reared it’s head (more later). I re-connected the keyer and just sent 1 «dit» then waited till the rig unkeyed, the plan being to discover how to involke the long «dah» bug.

After each successful test (no long «dah» sent) I then increased the speed of the keyer. I got to about 20wpm before the long «dah» bug appeared. With the above information I turned the keyer down to just under 20wpm and made a few cq calls. Ray GM0MNV up in Glenrothes came back to me and I enjoyed a successful cw QSO with him. Unfortunately this is where I discovered a second firmware bug.

The time to PTT from key closure is too long with the result being the initial cw character is chopped. If the first cw element you send is a «di» then this is non existant on the output (not good if you are working EA). If the first cw element you send is a «dah» then this is chopped. A work around is to always send an initial «di» before the start of every transmission (you can’t manually close the PTT from the mic in cw mode). Time from cw key input to PTT closure may be fixable in firmware or at least improved…V4?. There may be a hardware limitation of how much this can be improved, but we’ll have to wait and see. In the meantime I’ve worked DL, EA, HB, HA and GM all good fun.

Delay to open PTT at the end of transmission is about right and a speed of 18WPM-20WPM seems to work out fine without the PTT opening and closing during transmission (lower limit probably about 12WPM) however you cannot set this delay in the menu….V4?. I’m getting to like this wee rig, no real show stoppers, but it’s got a long way to go in terms of firmware improvement till it get’s to the capabilities of the worst cw ham radio. PS. I have since re-connected the manual keyer and found that the «long dah» bug can also be seem if a quick stab at the key is made. Please get in touch if you discover any work arounds for the above bugs or even if you need more detail on them. https://www.youtube.com/watch?v=yUEb-MjWuok

President Lincoln II V3 firmware bugs found…so far!

Well I’d like to share some more findings with you. Yet again the President Lincoln II V3 (cw mode) was nearly assigned to the bin. On listening to my transmission on another transceiver I noticed that the initial transmitted cw element was not only chopped, but the transmitted tone changed by about 200Hz like it was drifting or warming up.


On air it sounded very poor for the initial cw element then fine for the rest of the transmission. Just by chance I moved the clarifier and discovered that the initial cw element tone drift characteristic changed on transmit! I had the clarifier at 2 o’clock to allow me to rx returning cw stations, I centered the clarifier and listened to my initial transmitted cw element….no more tone drift! Yet another firmware problem! I thought about this a bit and came up with a work around…SPLIT! I set up a postive split of 600Hz (6 offset on the LCD) this meant I could work stations with the clarifier centered and avoid the initial cw element transmit tone drift problem.

Just to summarise all the cw problems found so far:

1)   Initial transmitted cw element chopped due to «PTT too slow» to engage.

2)   Initial transmitted cw element «long dah» independent of the key up/dwn position.

3)   Initial transmitted cw element «tone drift» due to non-centered clarifier.

With my work-arounds (in order):

1)   Send an initial dit before the start of every transmission.

2)   Increase the size of the initial transmitted cw element i.e. slow down cw speed.

3)   Center the clarifier and use a positive 600Hz split instead.

The good news is that once you implement the above work-arounds the President Lincoln can be used quite effectively in cw mode. Hopefully President will see this post and implement some fixes for future firmware revisions…please?

President Lincoln II V3 more findings

Ok with the second transceiver I realised that the President Lincoln II V3 cw mode is DSB (Double sideband). This means I can hear my second transceiver tx twice whilst tuning on rx with the Lincoln (-600Hz -> null -> +600Hz). My Lincoln menu item «CWtoFr» is set to «600». This is similar to some of the simple cw rx kits I have built in the past.

The trick is to decide which rx sideband to tune for and stick to that. I’ve decided to always tune to the hf side of the incoming cw station (clarifier centered and with split engaged (-600Hz offset)). This means I can go straight back to them and they will hear me. If the hf side has interference from another rx station then you can alternatively tune for the lf side provided you change the split to +600Hz offset.

Using the split function simply means that the tx frequency of the Lincoln is different to the rx frequency by the set offset and direction. Using this feature avoids the «tone drift» firmware problem during initial tx cw element described in a previous posting caused by using the clarifier. I’m learning all the time here and am pretty disappointed with «the best» cb offering for cw mode. There a lot of tx firmware bugs and the DSB rx is simply too crude a design for a transceiver of this price. CW Buyer beware!

http://gm0elp.blogspot.co.uk/

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