Here some measurements of diodes I have for crystal radio experiments. 
The SMD types are soldered onto a "surfboard",.. well all of them now.

Measurements are done to know the Rd of the diodes. Knowing the Rd you can select a correct one to match the diode with the 3 times parallel resistance of the LC circuit.
For instance: freq=1500Khz, coil=215H, Q=1200, makes Rparallel of 2430Ω. 3 times Rp makes 7291KΩ.
So a HSMS-2812 should make about the correct diode.
Then match that using a audiotransformer with same value.  If you have one.

The diodes I have are measured as Ben Tongue did, measuring the Saturation current and idiality factor. With these figures i can calculate the diode resistance at zero volt (Rd).
The formula used for this is: Shockley equation Id = Is*{exp[(qe/(n*k*TK))*(V-I*Rs)]-1} or simplified  RD = 0,000086171  x n x TK / Is.

Where:
RD = diode resistance at zero Volt (unit: Ohm)
n = ideality factor, the lower this factor the better.
TK = temperature in Kelvin (= temperature in C + 273)
Is = saturation current (unit: A)
qe = electron charge = 1.609E-19 coulomb
x = multiply

You`ll find Ben Tongues crystal radio pages here. See pages on diodes.

As for Article #16 on Ben`s pages, I edited the excel spreadsheet to calculate Is.
Here is the excel file.

 


Diodes below I have in my assortment are: 
 IS, Rd, n factor measured and calculated using Ben Tongues  #16 tool and above excel sheet.
Vf, If and Cj are taken from respective datasheets if available or DVM.
Some diodes give a ideality facor (n) lower as 1, presumably caused by losses inside my measering tool. This
is also seen with the measurements Ben Tongue made.


FO-215

With diodes with more then one in one housing, only one diode is in the sheet.
Others measured lower Rd, but that`s because they measured using higher forward currents.
.

Diode Marking Vf If Cj Is Rd Ideality factor: n
1I103B  (1И103А)              
1N34   0.29     1569nA 22KΩ 1.41
1N4001   0.57V     0.35nA 161617KΩ 2.25
1N4148   0.61V     1.33nA 27565KΩ 1.45
1N5711   0.38V 15mA 2pF 2.18nA 11462KΩ 0.98
3A117A              
3A119A              
5082-2370   0.36V     0.86nA 26942KΩ 0.91
5082-2800   0.372V 15mA 2pF 2.35nA 11309KΩ 1.04
5082-2810   0.34V 1mA 1.2pF 0.28nA 96576KΩ 1.06
5082-2816   0.41V 1mA 1pF 0.38nA 71970KΩ 1.08
5082-2824   0.2V 1A 1pF 0.36nA 84933KΩ 1.19
5082-2826         0.23nA 102560KΩ 1.08
5082-2835   0.34V 1mA 0.7pF 6.36nA 4003KΩ 1.04
5082-2900   0.4V 1mA 1.1pF 4.88nA 5158KΩ 0.99
AA143   0.33V 60mA 1.2pF 204nA 124KΩ 10.062
AA144   0.26V 45mA   731nA 41KΩ 12.032
AAY30   0.25V 110mA 1pF 258nA 97KΩ 0.99
BAS40-07 47S 0.31V 1mA 4pF      
BAS70-07 77S 0.375 1mA 1.6pF      
BAT15-03W not useable 0.17V 110mA 0.3pF      
BAT42   0.28V 200mA 7pF 52nA 518KΩ 1.06
BAT62 62            
BAT85   0.28V 200mA 8pF 57nA 436KΩ 0.98
BAT86   0.28V 200mA 7pF 29nA 924KΩ 1.06
D18   0.366 16mA 0.5pF 117nA 240KΩ 1.11
D311   0.196 80mA   1212nA 22KΩ 1.07
D9B   0.28     609nA 43KΩ 1,042
D9J   0.283     1669nA 17KΩ 1,11
DDC2353   0.21V 100mA 0.1pF      
Diode Marking Vf If Cj Is Rd Ideality factor : n
FO215 FO215 0,27V     77nA       333KΩ 1,03
Green LED (5mm)   1.8V     17.94nA 84762KΩ 60
HSMS-2804 A4L 0.33V 15mA 2pF 10.7nA 2280KΩ 0.97
HSMS-2805 A5Y 0.33V 15mA 2pF 22.8nA 1240KΩ 1.12
HSMS-2810 B0X 0.33V 35mA 1.2pF 3.64nA 7106KΩ 1.02
HSMS-2812 B2 0.33V 35mA 1.2pF 3.29nA 7123KΩ 0.93
HSMS-2814 B4b 0.4 1mA 1.1pF  2.77nA  9363KΩ  1.02
HSMS-2815 B5h 0.4V 1mA 1.1pF  1.96nA  12145KΩ  0.93
HSMS-2825 C5  0.31V      8.76nA  2949KΩ 1.02 
HSMS-282K CKY 0.34V 1mA 0.7pF 6.43nA 3944KΩ 1.01
HSMS-2850 P0 0.2V   0.3pF      
HSMS-2852 P26            
HSMS-2855 P5O            
HSMS-2865 T5W 0.29V     3.17nA 8150KΩ 1.02
HSMS-286K TKM 0.29V 1mA 0.18pF  20.3nA  1324KΩ  1.06
HSMS-286L TLL 0.29V   0.18pF  23.8nA  1124KΩ 1.05
LL-46-GS08   0.25V 0.1mA 8pF 42nA 628KΩ 1.06
ND4991   0.2V 30mA 0.8pF 467nA 64KΩ 1.19
OA161   0.42V          
OA202              
OA5   0.238V     1818nA 139KΩ 10+
OA70 (valvo)   0.31V 0.1mA   592nA 49KΩ 11.667
OA73         692nA 48KΩ 1.32
OA75              
OA79   0.3V     623nA 38KΩ 0.94
OA81         423nA 58KΩ 0.97
OA85         1079nA 28KΩ 1.19
OA95   0.25V 0.1mA   604nA    
Red LED (5mm)   1.8V     17.94nA 84762KΩ 60
SMS7630-001 SD1 0.16V 50mA 0.14pF      
               

To select different diodes or more in parallel I made a new switch assembly.

This assembly is completely made of teflon (ptfe). Put together using nylon screws.
Hardware are brass M3 bolts, nuts, and washers,  all silver plated. The input and output strip is 1mm thick copper, silver plated. Surfboard pcb also silver plated. Thumbscrews in picure are 8mm hexagon rod, need to make new ones using 6mm.

Contacts are reed switches operated by a neodymium magnet. With a second slider I can operate a second reed to put another diode in parallel.

All my diodes are soldered this way on a surboard with 2, 4, or 6 connections.

 

updated januari 2024