PL 600 is now my newest radio . I have bought it as a replacement of the PL550 which is used to my relatives in another city for reason to be as second radio to my De1102
The most peculiar with this order is that i bought from a local seller. this was not the funny but that he imported from Portugal as the instruction giude was in portuguese . There was also included a computer printout with the English guide with a ,but the letters were very small so that i could nt read them unless i used a magnifying lens!! Fortunately after much googling i found the same guide and printed it in full margins
There was also a small printed paper with two program changes to activate LW an AIR band. As i foound several uncommon features in its operation i could suppose the POrtuguese folk posibly did some internal adjustements to the radio (eg narrow band AM audio in wide band AM filter )
Here is a simplified report of testing both radios and also the differences I found between 550 and 600 (for which a separate article will be posted later )
The model I have now has some minor advantages over the 550 from the reception bands :
The built in software seems modified from the original PL600 design to activate the LW and VHF bands mainly 100-500 kW for LW and 118-137 for VHF using system code 09 to activate LW and system code 03 to activate AIR band . In a simple check the LW band has very poor reception and VHF was full of spurious from shortwaves !!!I expected to listen to some air frequencies in my home in Thessaloniki but the radio could not receive anything except harmonics ! (by using in parallel the Yupiteru 7600 all band scanner and checking for strong signals )
The FM band is the same as 550 and 1102 with 76-108 mHz with minimal images across the lower (vacant) band of 76-88. I kept this band also open since in Litohoron there is ability to listen to 2 stations from Bulgaria in this band.
MW : its steps are 9 and 10 kHz , software defined , but I left the step on 10 kHz to cover all the band
SW is 2000-30000 kHz in full span.The lower band can be traced by tuning down the 3 mHz ..
Here are my observations of the radio :
PL 600 vs de 1102
The box includes : radio , radio pack , earphones , mains adaptor and antenna in open reel form (you wind the wire over the reel ) and ears type antenna plugr (I disliked this design as other older models offered a true finger wounded as the meter measures with clamp)
this is a photo with the wire antenna in discussion
Frequency steps : On FM the step is 10 kHz and 100 kHz On SW the step is 1 and 5 kHz , on MW is 1 and 9/10 kHz , an AIR band is 1 and 50 khz . There are also 3 modes: fine step ie 1 kHz , fast step ie 5 kHz and auto mode , that depends on the speed you tune the frequency (either from the up own or from the tuning knob ) Scanning : scanning is made with the up down buttons with abt 2-3 steps per sec
Bandwidth : 4 and 6 kHz for AM bands. the funny is that the narrow band has less sensitivity than the wide band! Shown on the bottom right part . ON the Fm band it is used for Stereo /mono modes .
SSB and BFO : there is some sensitivity increase for these modes over the standard AM modes . In stronger signals audio is disturbed . BFO seems working to +-2-2.5kHz though i did n't test so far for the real span . Also the centered point for in freq ECSS is -0.5 kHz for a given radio station. This probably means the freq of the displayed station for the AM bands are has an error by -500 Hz and this possibly the reason that I have to tune out by 1 kHz in order to properly tune each station . SSB uses the older knob for antenna tuning. SSB us activated from the 2nd from bottom to top button
Battery indicator : the PL 200 and 550 shown the bar (right to the antenna symbol )as battery indicator m but this radio uses the battery symbol to indicate the battery level . IN just 2 hours the battery has dropped to 1 point!
Back light : it is activated every time press a button or the freq knob . It is one of its opration I hate most sine i think is one reason the batery dropped by one point !
Power : works the same way as other PL models : pressing once activates the sleep mode and with the up down buttons you determine the operation times . Pressing for 2 seconds sleep leaves the radio operating continuously
Timer : There are two times with this radio and are easily adjusted thru these 3 above buttons
Volume : Speakers have the same volume with the earphones Audio quality in the Fm band is good same with 1102 but on the AM modes the quality is vey bad. IN speakers audio is good either in AM or on Fm modes . In earphones audio is somewhet bassier than 550 and but on AM bass is somehow stonger from both
Tuning knob : a nicer design than the other PL models with a nice sense of touch Tuning does not have any cliks
Earphones : these earphones have a bad audio . Comparing to my best ears SONY MDR have a better design with a small metal part but audio is bassier and with less treble . False ! it filters audio down to 4 kHz max. If you wil use with other high fidelity radios iou will hear no trebles !
Frequency dialing : IN contrast to the other PL models you have here first to dial the number without the need to add the last zeroes and then press [enter] to dial ie for 10000 you can press only 10[enter] . With radio off , you can adjust the firmware and determine the memories and their banks , actviate the special bands , the clock mode and more.
And something about the band changing :keeping in mind the above photo the bands are changed from the AM FM (LW AIR) button on tbbottom right (above the SSB logo ) SW bands are changed from the button next to it
And some info on the left part of the radio :
Antenna connector : The antenna reel and a earphones type plugger . Although i did not used it.and the older model's clamp has broken , it connects here with usually good signals for Fm and SW bands only
Antenna gain : with 3 steps DX, normal and local (2 level attenuation) . And here is one bad design:You need to use it only for the DX setting otherwise the signals are very poor in the SW bands even with the external antenna ! The radio si not overloaded even if a 16 m antenna is connected on it ! The 550 model had easy overloads
Tone: trebled and bassy. Trebled audio is good for earphones especially for FM band though not so trebly as the LP550 . There is small difference with tomes on the Am bands
Ears output
Mains adaptor, using its enclosed adaptor of 6 V . It adds however some noise
Now testing with the DE1102 , i used my older diversity technique/theorem of using them this way:
Two radios are used close to other. Their telescopic antennas are unfolded in the same length / surface. Earbuds are connected into respective audio outs of radios one earbud is used for a head diversity audio. First audio is determined by a strong and clear station so that both single earbuds generate a mono sounded audio in your head (i.e. at the center ).This is what we can scale 5 at a scale of 1-9. If an audio is stronger in the left side will will rated from 1-4 and on the right side at 6-9 with 1 and 9 being the only sounded points. Under this theorem which audio is stronger , can mean a higher sensitivity towards the coresponding radio.
Using this theorem the 600 has been seton the left side and the 1102 on the right side with the follwing results:
MW
530 2315 2
891 2322 4
1323 2316 2
1565 2324 4
As in result i may suppose that PL has better sensitivity in all the MW band
SW
3905 2255 5
4828 2251 5
7030 2233 7
7125 2244 6
9500 2221 5
9830 2221 4
12140 2213 3
15190 2215 5
That might mean the Tecsun radio has nearly the same sensitivity with the DE radio , it lacks some on the 7 mHz band while on the 9-11mHz bands where DE has lower sensitivity Tecsun goes beyond
From the above analysis keep the following drawbacks , though as radio offer very good results :
1. Shifting error by -500 Hz (comes from the off tuned BFO )
2. Lower sensitivity on narow than wide band
3. Increased sensitivity on SSB , but some expense from intelligibility
4. Somehow lower sensitivity than PL 550 (look next article )
5. Very poor reception on the LW and nil reception on the AIR band once activated
6. Nice audio in FM and AM via speakers . Poor for AM bands via the ears
7. Supplied earphones are nice but not so good
8. AIR band seems nearly not working !!!
9 Somehow noisy mains adapter.
I still rate it as 4/5