Coax loss charts (from W3LPL)

Frank, W3LPL posted helpful coax loss charts to the CQ-Contest email list some time ago. I’ve used them extensively, particularly in deciding if it was necessary to use LDF4-50a hardline over RG-8. I’m reprinting this here, with credit to Frank, so it is not buried in the email list archives.

Note: charts may not format properly on a mobile device.

From: Frank Donovan W3LPL
 
Subject: CONTESTER's coax cable attenuation charts
 
 
 
I developed and have been using the following charts for some years.  
 
The CONTESTERs I've given copies to have found them most useful as 
 
well.  The first table is the common attenuation per 100 ft chart, but 
 
with specific values for each ham band.
 
 
 
The second table is in cable feet per dB, which can be very handy for 
 
tradeoff analysis (e.g. do I really need to use Andrew LDF5 for my 1000 
 
foot run to my Beverages or is RG-8X good enuf?).
 
 
 
The third table shows the results of just such a tradeoff analysis, each 
 
entry in the table represents the cable length in feet before Andrew 
 
LDF5 offers a 1 dB advantage vs the various cables listed
 
 
 
The last table is identical to the third table, except these trades are 
 
for Andrew LDF4.
 
 
 
Enjoy...
 
73!
 
Frank
 
W3LPL
 
 
 
                       
 
                            CABLE ATTENUATION  (dB per 100 ft)
 
           
 
             1.8   3.5   7.0  14.0  21.0  28.0  50.0   144   440  1296 
 
 
 
LDF7-50A     .03   .04   .06   .08   .10   .12   .16   .27   0.5   0.9
 
FHJ-7        .03   .05   .07   .10   .12   .15   .20   .37   0.8   1.7
 
LDF5-50A     .04   .06   .09   .14   .17   .19   .26   .45   0.8   1.5
 
FXA78-50J    .06   .08   .13   .17   .23   .27   .39   .77   1.4   2.8
 
3/4" CATV    .06   .08   .13   .17   .23   .26   .38   .62   1.7   3.0
 
LDF4-50A     .09   .13   .17   .25   .31   .36   .48   .84   1.4   2.5
 
RG-17        .10   .13   .18   .27   .34   .40   .50   1.3   2.5   5.0
 
SLA12-50J    .11   .15   .20   .28   .35   .42   .56   1.0   1.9   3.0
 
FXA12-50J    .12   .16   .22   .33   .40   .47   .65   1.2   2.1   4.0
 
FXA38-50J    .16   .23   .31   .45   .53   .64   .85   1.5   2.7   4.9
 
9913         .16   .23   .31   .45   .53   .64   .92   1.6   2.7   5.0
 
RG-213       .25   .37   .55   .75   1.0   1.2   1.6   2.8   5.1  10.0
 
RG-8X        .49   .68   1.0   1.4   1.7   1.9   2.5   4.5   8.4
 
 
 
 
 
                            CABLE ATTENUATION (Ft per dB)
 
 
 
             1.8   3.5   7.0  14.0  21.0  28.0  50.0   144   440  1296
 
 
 
LDF7-50A    3333  2500  1666  1250  1000   833   625   370   200   110
 
FHJ-7       2775  2080  1390  1040   833   667   520   310   165    92
 
LDF5-50A    2500  1666  1111   714   588   526   385   222   125    67
 
FXA78-50J   1666  1250   769   588   435   370   256   130    71    36
 
3/4" CATV   1666  1250   769   588   435   385   275   161    59    33
 
LDF4-50A    1111   769   588   400   323   266   208   119    71    40
 
RG-17       1000   769   556   370   294   250   200    77    40    20
 
SLA12-50J    909   667   500   355   285   235   175   100    53    34
 
FXA12-50J    834   625   455   300   250   210   150    83    48    25
 
FXA38-50J    625   435   320   220   190   155   115    67    37    20
 
9913         625   435   320   220   190   155   110    62    37    20
 
RG-213       400   270   180   130   100    83    62    36    20    10
 
RG-8X        204   147   100    71    59    53    40    22    12
 
 
 
 
 
             FEET REQUIRED FOR 1 DB ADVANTAGE LDF5-50A VS:
 
 
 
             1.8   3.5   7.0  14.0  21.0  28.0  50.0   144   440  1296
 
 
 
LDF4-50A    2000  1430  1250  910    715   625   435   250   165   100
 
RG-17       1666  1430  1110  770    560   475   420   120    60    30
 
FXA12-50J   1250  1000   770  525    435   355   255   120    75    40
 
9913         835   590   455  320    280   220   150   85     53    29
 
 
 
            
 
             FEET REQUIRED FOR 1 DB ADVANTAGE LDF4-50A VS:
 
            
 
             1.8   3.5   7.0  14.0  21.0  28.0  50.0   144    440  1296
 
             
 
RG-17         -     -     -    -     -     -     -     220     90    40
 
FXA12-50J     -     -   2000  1250  1100  835    625   250    145    65
 
9913        1430  1000   715   500   455  345    235   135     75    40
 
RG-213       910   600   285   200   150  120    85     45     20    12

Also see my article: Proper feeding of non-resonant antennas

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